Bicycle Mechanics - chain breaking gone wrong

I've tried searching through the forum to figure this out, but that just left me more confused, maybe someone can clear some things up for me, here's the problem:

i was removing the chain on my bike, and accidentally pushed the pin all the way out of the chain, what are my options? the chain says sedis on the side of it, and it's an older 12spd road bike. will the pin go back in? (and is it safe to ride like that?), can i buy a replacement pin (are those shimano replacement pins just for shimano chains?), if i bought a powerlink connector would that work with my bike/chain? thanks!

putting the pin back in is very hard, but you can try it.

you can also just take out the rest of the link and reconnect the chain and leave yourself with a shorter chain, which may cause problems or may not.

i dunno about replacement pins. maybe take this as a good reason to replace your chain?

Okay, I did this once, it's not super hard to fix but I can't vouch for what it might do to your chain link. First off, are you sure you're not due for a new chain, because why not do it now.

Or try this: Get a hammer and a pair of needlenose pliers. Lay out the chain on a wood surface, you are going to pound the pin back in. Set the chain together how it was before, with the two halves of the link connected. Now grab the pin with the pliers and align it with the hole in the link. Tap it back into the chainlink and finish the job with a chain tool. Worst case scenario, you ruin the link and buy a new chain. It will probably work though.

if i bought a powerlink connector would that work with my bike/chain? thanks!

Probably the best solution, if you can find a powerlink that's the right width. Measure your chain with a caliper. Personally, I'd push the pin back in, using a vise or chain tool (takes some dexterity).

It is possible to get a sedis pin back into a link but it weakens the chain and is a fiddly business.
You may have enough chain to discard one link. See parktools for a chainlength calculator
http://www.parktool.com/repair/readhowto.asp?id=26

The best option is probably a Power Link. This is useful when you need to remove the chain for cleaning. Practice spliting the powerlink with the clean chain, off the bike.

You probably have enough chain to lose a link. No guarantee that the pin, if you do manage to push it back in, won't fall out again. Be safe a new chain is a good upgrade.