Just nuts and bolts, don't need a service manual.

 Yes, the bolts may be seized into that aluminum housing, that will probably be your worst problem of the whole deal, althought the removal of the rear, oil cooler o-ring/sleeve, going into that 9Y4065 cover, will probably make you cuss a little, too.

It's been a long time since I have done one of these. They aren't a common failure, at all. I do remember having a couple of bolts that were stubborn, or stripped out. I also remember that don't be surprized when you remove that plate/cover and it looks warped/curved lenghtways. Just be careful, and gentle cleaning the gasket; it is pretty thin, long piece of aluminum. Try not to over-sand/buff it, when cleaning either aluminum surfaces. You want to end up with two nice "flat" surfaces for the new gasket to be crushed inbetween.(even though that 9Y4065 cover will have a curve to it , until you bolt it back up.)

Now, there is always the possibility of pitting on the inside, once you remove it and will need to determine IF you must purchase a new one. (Depends on how well the coolant as been taken care of and the quality or lack of quality of the water being used in the cooling system, over the life of the engine.)

I will add a couple pictures of parts, that may or may not be your style of oil cooler, but you can kinda see the breakdown of things with these photos.

(3176 _7LG_serial_number_prefix__9Y4065 cover.jpg)

(3176 _7LG_serial_number_prefix__oil_cooler.bmp)

(3176 _7LG_serial_number_prefix__water_lines.jpg)

3176 _7LG_serial_number_prefix__9Y4065 cover.jpg (58KB - 548 downloads)

3176 _7LG_serial_number_prefix__oil_cooler.bmp (88KB - 576 downloads)

3176 _7LG_serial_number_prefix__water_lines.jpg (37KB - 427 downloads)