Wheel hub change

Help!!!

Two of the rear wheel bolts are stripped. I got the dealer to re-tread the holes for me earlier the year. However now is complete gone (thanks to tyre shop guys). I can loosen one of the bolt by hand now.

Now I have got a 2nd hand hub with bearing and some good wheel bolts from the wrecker. I have checked the workshop manual which looks pretty straight forward to do it. The bolt to hold the hub seems hugh (looks like 34 or 36mm).

My questions are:
1/. If I just undo the rear caliper, do I have to use special tool to push the piston back when put it back? or just simply put it back without problem?

2/. Is it hard to replace the hub? It looks only one super hugh bolt to hold it. Do I just undo it, replace it then tighten it?

Reason I want to do it myself is dealer is booked out this year. Also it is waste of money to get them replace the 2nd hand one.

Help!

Yes, you will need something to press the piston back, the complication is the handbrake.

But I only undo 1 side.

Do you mean once I undo the bolt on the rear caliper and remove the caliper. It will automatically put in and I won't able to put it back unless press the piston back by using a wrench or something?

Well, I'm not an expert, I just watched my friend do mine and I guess you might be lucky, if not you'll need a tool to retract the piston. Hopefully someone with direct knowledge will be defintitve. I know in the case of my car he was having major issues getting the piston back before he rigged up a clamp to do the job. From my observation, the piston only has to move a smidgen and the caliper won't go back on.

Im not sure on the 147 but most rear hubs are a press interferance fit, so once you have the hub off youll need to press the old one out and press the new one in. Probably not the sort of job you can do yoursels unless you have a big old bearing press.