Toyota Repair: manual transmission, toyota celica, salvage yard

Question
Was wondering where i can check the manual transmission liquid for a toyota celica st '90 1.6 v. engine.  The clutch skips out of gear when i am in 5th gear.

Thanks

Answer
The fluid can be checked by removing the fiil plug on the transmission, it's located towards the front of the car near the radiator on the side of the transmission, it's a 24mm size plug, do not remove the 12mm size bolt. I really don't think that the fluid is the problem there is a mechanical problem with the transmission, in most cases jumping out of 5th gear is caused by worn shift forks or shift sleeves and gears which would require disassembling the transmission to repair it(very expensive), it may be a better idea to just replace it with a good used transmission from a salvage yard.