2) Where is exactly the bleed nipple located and how does it look like? Is it covered with some special cap?


They should be obvious. They may or may not still have a rubber cap on them.

3) Do I need special wrench, or can I use a box wrench and what size?

Box wrench would be fine. Have some lengths of clear hose to direct the old fluid. Be gentle with the bleed screws.

glenmore
1991 300CE