Unless it's a particularly rare or precious-to-you lens, the costs of a professional repair/CLA is likely to be much greater than perhaps just buying another one in better condition.
As you're in the US, you could start by looking at KEH's repair service. Or google ?
Unless some of the longtime pros/film users here can chime in with other suggestions.
Failing that a post at RFF or Photo.net will probably get you a zillion suggestions.
I have a 50mm 1.7, the single most common rokkor in existence, that had fungus in it. I got it with a few other things all bundled together, and didn't need it, so it didn't matter if I screwed it up. So I took it apart and cleaned it, which actually worked very well and took maybe 15 minutes. If you have tiny screwdrivers (like a 0 or 00 phillips), that's pretty much the whole battle. Depending on whether you want to go in the front or the back, you'd also need a smallish flathead to turn the plastic conical shaped piece that holds the front elements in.
But if this is a 50mm 1.4 or 1.2, or a 58, or a 24, or an 85, etc... probably worth paying someone.
It's an MD (II generation) 200mm f/2.8 Tele-Rokkor, don't have it with me right now so I don't remember if it's a Rokkor-X or not (probably not). Image quality is pretty good, condition of the lens (focus stiffness not withstanding) is very good, so I don't consider it disposable.
I've been considering looking for a good 180mm f/2.8 and a 135mm f/2.8 if I can find good prices. I could see the 180 replacing the 200 in my bag but I wouldn't get rid of the 200.