The New York Rangers stripped the Montreal Canadiens of their home-ice advantage, and their mystique, today. The Rangers never looked troubled as they crushed the three-time defending Stanley Cup champions, 4-1, in the opener of the best-of-seven final.

Relentless forechecking, especially against overworkeed defensemen Serge Savard and Larry Robinson, contributed to numerous Montreal errors. The Rangers capitalized on enough mistakes so that, with John Davidson's 31-save goaltending, they had a relatively easy time.

"It wasn't easy," insisted Ranger Coach Fred Shero. "Maybe it looked easy. It could have been easy, if we had taken advantage of all our break aways in the second period. There was some nervousness, I guess."

There was evidence of nerves in the mightly Blue, Blanc et Rounge, too. The first three Ranger goals resulted from two errant passes by Robinson and another by Mario Tremblay.

"This wasn't my toughest game, but I certainly had my toughest time," Robinson said. "Nothing was bouncing the way I wanted it to. I'm used to getting the bounces."

We made bad mistakes and they capitalized," said Montreal Coach Scotty Bowman. "It wasn't even a case of their forcing us. We just made bad mistakes."

The principal victim of his teammates' errors was goalie Ken Dryden, who departed after the second period with the score already 4-1.

It was the first time since he joined the Canadiens in 1971, except for a year of temporary retirement in 1974, that Dryden had sat out a period of playoff hockey. Bunny Larocque, who relieved him, already has been tabbed as the starter for Tuesday night's second game here.

Dryden was booed during the introductions and, after the first two goals, was subjected to derisive cheers whenever he touches the puck.

Tremblay was serving the game's first penalty, for slashing,when Robinson's attempted clearing pass struck the Rangers' Anders Hedberg in the right-wing circle.

Hedberg quickly whipped a pass to Steve Vickers, who scored from just outside the crease. Robinson, the most valuable player of the 1978 playoff, normally does not skate on the penalty-killing shifts, but he was today because Guy Lapointe is ailing.

"We made it easy for them to get in front," Bowman siad. "The penlaty on the slash, then we had two chances to clear and didn't. Robinson was in an unfamiliar position and he didn't take his time.

That goal came at 6:28. By 14:27 the Rangers had enough goals to win. Defenseman Ron Greschner intercepted a Tremblay pass inside the Montreal blue line; when nobody picked him up, he skated within 30 feet and drilled a shot past Dryden.

The Rangers had three breakaway chances to pull farther ahead early in the second period. Don Maloney came out of the penalty box and grabbed a puck that had squirted through Robinson, but he waited too long to shoot and, after veering left, fired over the net. Ron Duguay hit the far post on a break down the righ wing and Pierre Plante shot wide on a shorthanded dash down the left wing.

So, when Guy Lafleur took Jacques Lemaire's drop pass and beat Davidson with a 40-footer, a carbon copy of the blast that sent Boston into overtime to lose, the 17,00k fans were primed for the usual Montreal come back. It never came.

Less than 2 1/2 minutes later, the Rangers regained their two-goal lead. Robinson made a bad pass off the side boards and Ranger Mike McEwen intercepted it. He passed to Phil Esposito in the right-wing cicle and Esposito, after a lengthy pause, fired just as Savard dropped to block it. The puck went through Savard's legs, past a screened Dryden, and became Esposito's 57th Stanley Cup goal.

Dave Maloney compled a three-on-two break with Walt Tkaczuk and Headberg for a shorthanded score at 12:32.It was the Rangers' sixth shorthanded goal of th playoffs, a Cup record.

"It was a big goal for us," Maloney said. "We've scored a few shorthanded goals their years and it's a lift for you. It looks good when it goes in. if I'd been caught, it might have been a three-on-one the other way."

It might not have mattered, the way Davison was playing. In the third period, Lemaire sent a perfect pass to Lafluer at the finish of a two-on-one break and Davidson somehow kicked the shot away with his left skate. Playing his 14th game of the playoffs, a Ranger record, Davidson was reducing his goals-agaisnt average to 1.68.

Robinson called the Rangers "pretty good forecheckers. The Flyers used to thrwo everything at you, but the Rangers check much more interlligantly. They've got everybody going, and it we expect to do well, we have to get our act together and play better collectively, not just a smidgen here and there."

"Out players were aware of the key men the Canadiens have and they took every opportunity to run into them," Shero said. "A guy like Duguay gets the worst of it when he runs into Robinson, but at least he runs into him, and eventually it takes something out of Robinson.

"Let's face it, we're a well-coached team. We have six coaches on the ice, plus Mike Nykoluk. If you were in our dressing room, you'd see how well the six coaches (Dave Maloney, Esposito, Tkaczuk, Vickers, Carol Vadais and Pat Hickey) are handling the young guys. On other teams the palyers are afraid to open heir mouths. They let the coach say it. Here I just change lines." CAPTION: Picture, Ranger Steve Vickers beat fallen goalie Ken Dryden for first score of game. UPI Picture 2, Guy Lafleur, left, of the Canadiens and Don Maloney of the Rangers hold sticks high as puck bounds at their feet. AP