Firstly, it won't move fore/aft because there's a circlip behind the front pulley. Use a 2 or 3 leg puller to get the drive pulley off the shaft and then remove the bearing wire "clip" behind it. This is steel on steel so you can apply some heat if needed to help things along. I can't see you cutting the shaft off without an angle grinder cutting disc.
Best practice now is to heat the cover, boiling water would be find should you have enough available but I've either used a paint stripper hot air gun or before that, a propane torch. (smelly
) Whatever expansion you can get into the aluminium is good.
Then you can press out the bearing shaft which should take the impeller, seals and bearing with it. You need a press and good support on the aluminium front cover. I used a massive old fashioned 6" vice because you don't need a lot of force, just that it needs to be applied nice & squarely.
Brian