Hi guys. I come into this chat a little late but someone may find my experience helpful. Mine is a 97 Techno.
If you try to punch the bearing out you are actually hitting the aluminum spacer and will damage the end of it where it slides into the spacer tube. Also the disk brake side has a large circlip holding the bearing in. It needs to be removed before the bearing can come out.
I ended up taking mine to a bike shop as well but they used a Slide Impact Hammer (Avaliable from your local bearing supplier. Not cheap) to pull out the aluminum spacer. That allows the bearing protection cover to come off allowing access to the circlip. After removing the circlip the bearing can be extracted with the same tool. The second bearing is then a simple punch out from the other side.
In future I will simply take mine back to a bike shop. They do the job quickly and quite cheaply.
