power gear levelers seal kit for rebuild ?

The spring is a non issue. It comes off with the Jack. This link directs you to the LCI(Powergear now) web page for determining which kit you need. You WILL need a heavy duty Vise and probably a torch to break the lower collar loose to unscrew. I have always been able to clamp the cylinder in a large bench vise and use a LARGE pipe wrench with a 8 foot cheater bar to break them loose. It may be easier for you to get the parts and have a local Hydraulic shop do the actual repair after you remove the jack/s. Doug

https://www.lci1.com/assets/content/support/technical-information-sheets/Power_Gear/Leveling/82_L0352_Seal_Kit_replacement_Manual_.pdf