Try loosening the bolts on the pan so that it is hanging and there is space between the pan and your block but it is not detached all the way. You can drain the pan first. Get some RTV blue silicone sealant and spread some where it is leaking with a butter knife or whatever thin spreader you can think of. Don't be cheap with the silicone rubber, you can trim off the excess later. Tighten bolts to spec.