How can I replace a load bearing wall to open up a space?

Yes, this sort of thing is possible if the wall is replaced with a beam, but it’s serious work that demands judgment honed by experience. It’s necessary to make the same sort of beam-size calculations that a builder would have done if the home was originally framed as an open area instead of enclosed by a wall. The Canadian building code includes tables with specs for this sort of work, and understanding them isn’t difficult. Supporting the area while removing the wall and installing the beam will be the trickiest part of the task. It will probably also be necessary to make special arrangements to support the beam solidly at either end.