My Sealey 2tonne trolly jack isn't lifting well at the moment. It takes loads of pumps to get it a small amount.

I've got some hydrolic jack oil but i'm unsure how to go about filling it up.

The jack has two caps from what i can see. One takes a large flat blade screwdriver and the other a large 10(ish)mm hex drive.

Ideas?

My jack (Halfords) has a rubber bung half way along the cylinder. My engine crane has the same and that's where I top up with Hydraulic fluid so I suppose the jack would be the same.

Bet you wish you'd not thrown out the instructions now

Fortunately Sealey and google are your friends.
e.g. http://www.sealey-tools.co.uk/instructions/1250CX.PDF