Will this fix my 5.9 magnum oil leak?

some of the studs have an internal drive, you simply put a 3/8 extension in it, and put a ratchet on the other end

if it has an eternal hex drive you are in for a knuckle busting treat, they are a paint to remove
(you need a 1 inch socket, i believe and you may want to hit it on a belt sander to get the internal bevel of the socket ground off so you get a better grip on it)

now, to answer your question, i really dont know if that will fix your leak or not, because we have no idea where you are leaking from

have you checked to make sure there isnt a filter seal left on there from a previous oil change?

(i helped a buddy with a leaking oil filter on a mid 90s duster and we found 3 O rings, between the filter and the block)

i have also had a leaking rear main, that would drip onto the torque converter, which would then fling it up onto the filter...and since the filter is the highest point i saw oil, guess what i thought was leaking?