Husqvarna 23 Hp 48" Deck Yard Tractor "oil leaking housing filter connects" Questions

...oil rings are no stuck on the housing, and there's a o ring that comes on the new filter, pre lube the filter o-ring and install,,, if it the hydralic housing or pump, check for hair line cracks, ...

...oil filter where it screws into to housing. Using a small headed hammer, or anything else such as a cold chisel that has some weight to it, gently tap around the housing using a lot of small taps ...