1988 blazer 2.8 .do i need any special tools to replace bearings in the alternator.

 

2x paperclips, and a socket set.

Crack it open. Use sockets the same size as the berring to knock out the berring, and same to reinstall. I mean a socket the same diameter as the outside of the berring and hit the socket with a hammer.

You notice those 2 springs with little blocks with a "u" shape that came out when you opened it? Those are brushes. Put em back in the shell, and there is a hole you can stick the paperclip in to hold the brushes back.

Put back together and pull out the paperclips.