On my Donaldson filter, it lays horizontally just inside a side access door. The 4 bolts to remove the bottom of the filter is right there. The problem I have is the filter element is a conical element with the skinny side facing out. It would not stay up to put the cap back on. I just made a small piece of wood to hold the element in the correct position to be able to reinstall the cap and 4 nuts. I don't know how yours is. Good Luck, TomC
That is the same basic problem I had. Did you leave the wood inside? It seems like the foam gaskets fit really tight and make it hard to get the cover back on.
I'm wondering how a mechanic does it?