Not sure what you mean.
If you want the mechanics of the gun put back in factory condition, Colt can do that for you.
Since they built the gun, NO ONE knows more about it then they do, plus they have all the parts and tooling to do the job RIGHT.
Price and turnaround is very good, with repairs usually running about one month max.
As for doing it yourself, that depends on what's wrong, and what needs to be replaced.
This can be as simple as giving the gun a deep cleaning, and replacing all the springs, to major parts replacement for parts badly damaged or switched out for non-original parts.
If you want the satin nickel finish refurbished, that's not possible.
Colt used Satin Electroless Nickel, also known as "Coltguard".
Like all plated finishes, once it gets ratty looking, all you can do is have it stripped and refinished.
Again, Colt can do this and have it looking factory-new.