It would be way easier to rebuild/check with it out on the bench. If you have a column floor cover that screws in place, the box will come out easily. Steering wheel could stay on. Read manual. Disconnect column harness. Take off pitman arm nut and use puller to remove pitman, take out 3 box mounting bolts, then unbolt column from dash and thread column/box up thru floor. 3 on the tree? more work. If the bearings are still OK, I don't think the sector or pinion are usually bad so if it's just leaking, replace lube with thick lube and re-gasket and adjust. The gaskets are easy to make/copy with thin gasket material.
The rebuild kits are about $65.
