Yep!
Remove head Remove oil pan Remove wrist pins and push piston up out of the head
can you tell me if rear caliper piston screws in
You need a special brake piston tool to do this. Here is a link that shows what this tool looks like: http://www.lislecorp.com/tool_detail.cfm?detail=416 Basically, you put this on the end of a 3/8 inch drive, then use the side of the tool where the pins match your brake piston. Engage the pins from the tools into the piston slots, press in and turn clockwise. It will take a lot of turns to move it back in the bore.
There are three types of piston pins they are, Stationary pin Semi floating pin Full floating pin
Remove the two pins going through the pads. Pull out the old pads, push in the piston and install new pads, replace pins with the clips.
If you have all the parts out and clean. I have see it done. Freeze your wrist pins. heat your piston rod. Assemble quickly. This is the only way I know how with out a press.
To keep the rings from rotating on 2 stroke engines. You will not see this on 4 stroke engines.
There are three types of piston pins they are, Stationary pin Semi floating pin Full floating pin
The number of pins at the bottom of the stick. Some ddr's have 184 pins, some newer models have 240, starting with DDR2.
Calipers do not have a grease fitting. The only fitting is a bleed value and this is for brake fluid to come out of when you bleed the brakes. I bet you are trying to lube the caliper pins. Simply remove the pins holding the caliper on and use the appropate brake lube. You can pick up the correct lube at you local parts store
You probably have frozen brake caliper slider pins or a frozen brake caliper piston on one side.