Might oughtta put the two long bolts back in.. they hold the starter together. If it comes apart, it can be a bit tricky to reassemble. If memory serves, you should be there only the o-ring seal might be sticking in the case... might try some penetrating oil and some wiggling. Also, you may have to remove the oil cooler line to get it out.
Be aware that when it comes out, it's going to dump some oil so have a pan ready.