My previous homemade tools (I eventually coughed up the money to get some real tools, but these worked in their day):

Get a length of 1.25" diameter copper pipe (about 12" long), cut 4 slits in it lengthwise. Get a pipe cap for the other end, epoxy on the other end if it doesn't press fit securely. Cut the handle off of an old wooden baseball bat, hammer copper pipe onto baseball bat. Voila! Head cup remover. Copper is soft enough not to damage most head cups or frames. Won't last nearly as long a Park or VAR one, but is perfectly fine for home use.

A long bolt, nut and a stack of washers can make an effective press. I used washers big enough to contact the outside of the headset cups. Be careful though, some aluminum cups are very thin and can bend if pressure is applied here. Headset presses come with stepped bushings that apply pressure to the cup skirt (if they don't have a cartridge bearing already pressed into the cup). I usually press one cup in at a time.

Removing the crown race can be a ***** sometimes. A dull knife blade works on suspension forks, followed by a flat-blade screw driver you don't care about screwing up (heh, no pun intended) or a small chisel punch.

For installing the crown race I had an old frame tube that happened to be the right diameter for 1 1/8". I've heard of people using PVC, but I'm not sure if you can get PVC pipe with an ID of slightly larger than 1 1/8". Some crown races on cartridge bearing head sets are soft aluminum and can be damaged from direct impact. For expensive headsets, this may be the one task to have a shop do.