Q:

I think my clutch is failing, how can I tell what needs to be replaced?

I have a 2000 Mazda Protege with a 5-speed manual transmission.  In recent months, I have noticed something that I believe is the clutch slipping.  Sometimes when I am accelerating to highway speeds, one of the gears will not want to "seat" so the RPMs stay kind of high unless I back off the gas for a bit.  More recently, when accelerating up a hill, the car will occasionally try to come out of gear (RPMs go from ~3000 up to over 3500 and the cruise will usually shut off).  Am I correct that this means the clutch is wearing out?  I have not noticed any of these symptoms when not going highway speeds.  There are no weird noises (besides high RPM), no bad smells from driving, and it shifts into all gears just fine.
Assuming that these are symptoms of clutch failure, how likely is it that I could fix this on my own?  I have a decent amount of mechanical experience, but I've never done any transmission work besides a flush and filter on automatics.  By experience, I mean I have repaired or replaced most external components on the engine, and done brake, axle, and steering repairs.  
Can anyone give me an idea of what parts would need to be replaced for these symptoms and how hard it is to do?  Are there any other diagnostics I can do to further tell what parts need to be fixed?

A:

If it is a slipping clutch it will get worse soon, and you will know for sure, from your description, yes it is slipping.
Yours is a FWD car, they are a bit more difficult than a RWD most of the time, you will need an engine support bar to hold the engine while you remove the transmission, after the trans is out this support bar will suspend the engine so it does not hang on the motor mounts or even fall out on the ground. This is the most important tool you need.

As far as parts, clutches are sold in Kits here in the USA, it has everything you need including the disc alignment pilot tool. Kits I buy come with a Pressure Plate, Clutch Disc, Throw Out Bearing (when applicable), and a clutch pilot tool.
Once the trans is out and the pressure plate and disc are removed, you will see the flywheel, it has a surface that the clutch disc wears down, to do a first rate job, pull the flywheel and take to an Automotive machine shop to have it resurfaced. Careful when removing it is heavier than it looks.
This is a difficult job if you have never done one before, but if you have the time I am sure you can do it.

