Hi, What has been said about the rears is good advice. Presses do help keep things controlled, but if you don't have access then the following will help.
Depending on whether you want to build up a really useful workshop of tools or not, then one of these can be a good investment:
https://www.amazon.co.uk/Bearing-Puller ... 03HYFQ0ELE. Other sources /makes are available.
For the front wheel bearings:
If you have a model with cast wheels, then there can be a build up of corrosion outside of the bearing on the speedo drive side that makes the bearing particularly tight to remove, and in extreme cases it can 'burst' the speedo drive gear wheel when you do move it.
The best thing to do is to use a 'Dremel' or similar to remove any powder coat and /or corrosion from the hole outside of the bearing first. This may also apply to spoked disc hubs and drums too, but as I haven't ever worked on those I don't know.
Next, If you don't have a bearing puller, the following works quite well. Do the non speedo drive side first - its bore is shorter and you can then drift out the right hand bearing much more easily.
On the cast wheel models there is a large circlip to retain the LHS bearing. Don't forget to remove this first. The same comments about corrosion in the bearing bore as for the speedo side still apply, but usually it isn't so serious.
Using a lever, push the internal spacer to one side so that you can get to the inner edge of the bearing, then with sharp ended drift and a series of firm 'whacks' with a hammer (working your way around the bearing so that it comes out 'square' to the hole, the bearing will come out fairly cleanly.
Then, using a drift that is larger than the spindle, (some people will resort to a large socket and an extension bar, but I don't like abusing my tools....) you can persuade the right hand bearing out of its seat. The same comments of keeping it 'square to the hole' apply and it is important as the hole is much longer.
For refitting, put the bearings into the freezer the night before and they should go into their holes without any drama.
Hope that this helps.
George.