If you need to ask how to remove a starter, you really need some knowledge of basic mechanics, and a manual on THAT engine. Whatever you do, please disconnect the battery before doing anything.
No one rebuilds solenoids, they are not rebuildable. You replace them. Knowledgeable mechanics would never replace one without also disassembling the starter to make sure its not part of the problem. If you install electrical parts, they are not returnable. If you install the solenoid and still have starter problems, you just threw money away on the solenoid. And because labor is higher than parts costs, its cheaper to just put a whole new starter in right from the beginning. Not having a mechanical background or knowledge about these things, it would be wiser (and cheaper) in your case, to order a complete rebuilt starter from a reputable source, and replace the whole thing.