So... I had the all well known problem of the slow (sometimes fast) leak coming from under my '98 VR6. Which as many people know turns out to be the good ol' oil cooler seal -from the cooler to the block- And I searched the forums for an answer only to be let down by old threads that didn't really explain much.
Now, I THOROUGHLY APOLOGIZE because I was in a bit of a rush and didn't get a chance to take photos of the procedure, since this is my daily driver and I had to get it all done before heading to work... But I will do my best to give you some inside into doing this, pain in the ass but necessary, swap.
1. If your engine is like mine -AAA- this (below) IS NOT the right diagam. It belongs to what I believe is an MK4, and I was very confused when I was looking for the right part at the store.
2. This (below) is the right diag for my car '98 Jetta GLX -mk3-
Notice the big difference in how the oil cooler systems are.
3. Regular procedure at first follows how you would normally change your oil.
i.e. Jack up you car to a safe position, preferably use jack stands, unscerw plugs (pan and filter), let oil drain completely, then use 36mm socket to "unscrew" filter housing.
4. Following the "right" diagram (above) You will find that it's a bit of a tight squeeze to get to the oil cooler cover (#24, in the diagram) that holds it in place which requires a 32mm or 1 1/4" socket for it to be removed. You CAN still get your hand, the socket, and a ratchet in there in there past the radiator support to get it loose. Have some patience, it shouldn't be too tight. You won't have to strain too much getting it out. Be careful when taking the cover off cause some oil WILL come out of there, so keep the draining pan or some towels handy. Some covers come with a seal that will need to be replaced also (#3 between #24 and #25). Mine did not.
This is the oil cooler cover.
5. Once it's out you"ll notice the cooler assembly is still hanging there by its hoses. Don't worry, as long as you don't put any pressure or yank on it, nothing bad will happen. Try to pull it away from the block and you'll see that damn bad seal that keeps letting precious oil piss out of you engine. You should be able to pull it of with your fingers and then replace it with the new one. DON'T forget to rub some new oil on it before installing it like you would with any other seal. The Two tabs should secure it in place whilst you put the oil cooler and its cover back on. Torque the cover to a recommended "somewhat snug" aka 18 ft/lbs.