I have a L185 and the L245 has the same type of filter in the transmission case. Look where the hydraulic pump is on the rear side of the engine. Follow the pipes from that back to where it attaches to the transmission. Then on the opposite side of the tractor in the same location you should see a small cover bolted to the side of the transmission with a dome shape.
On the L185 it is on the left (sitting in the seat) side at the back of the foot board. I assume it is similar on the L245.
Unbolt that cover and there will be a o-ring for sealing that to the transmission. There will be a spring installed to hold the filter in. Sticking out of the transmission should be a small protrusion that you pull out (the end of the filter screen). You may need to grab it with needle nose pliers.
The filter is a tube of fine mesh that can be washed if it is still intact.
I would suggest that you get a new filter, o-ring and replace those if you have the time to wait on the parts. I would be afraid the o-ring would fail if not new.
For future reference - go to Kubota.com, parts, illustrated parts list and agree to their legal terms. Search for L245 then select you more exact model (l245DT) and you will get the parts list for your tractor in sections. You can also search by part name by selecting some obscure term like "book search" and using the pull down selections on that screen.
Oh and say hello to your brother Darrell and your other brother Derryl
