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?