First time doing air shocks, need help :)

Hey guys, first off thank you for taking the time to read my post I appreciate it.

Alright, so I have a 1982 Spectre 750 that blew out one of the shocks (was its time to go) So My plan (and so far it has worked) is to take the old shocks from my dads 2001 Voyager (same length) and swap them onto my bike. I am not stealing them from him he put progressive coil overs on his now. The way his shocks were made to work is to have one schrader valve that does to one shock and a tube that connects to the other shock to even the pressure. The spectre has one schrader valve that sits in the middle and has two lines, one for each shock. I took and connected the "new" shocks to the old lines leaving a hole open which I just plugged with a 8mmx1 thread bolt. Now my question is how do I add oil to these shocks? Some spilt out when my dad was taking them off his bike and I really don't want to screw them up. can someone walk me through step by step? thank you