I've been putting this off for over a year and from googling it the whole thing seems supremely complicated and I don't even know where to start.

I have an updated birth certificate with my current name and gender and I think I still have the original paper copy from when I was born. I have my old passport which is still valid. I also have other supporting documents like driver's license with my correct name and gender.

Some other things I don't understand - if I use a birth certificate as a supporting document, they need the original and not a copy, so does the physical one given to me with my changed name and sex count as an original? And if the name change means I need to get a new passport instead of renewing my old one, does that mean I also need to do all the extra steps like getting references to vouch for me, having things signed by a guarantor, etc?

And can I get all this done in person at a ServiceCanada or something? And hopefully they can walk me through anything I'm missing?