Testing it is all very well, but if it is high, then to do something, you will have to do it yourself, and if you don't know what the cause of the problem is, then it may well just return!
There is a lot of info online, would suggest looking for a specialist forum for more detailed help, it's not something you should even think about if you are not the researching and detailed technical type. It means taking T3 exclusively, (NOT slow release) and it isn't a joy if only for the 4 or 5 times daily dosing, as well as never feeling sure what is going on, and whether your are actually hypo or hyper!
Testing is (or was then!) expensive.
I went through this process almost 3 years back, and it meant lots of ups and downs, and one false alert of being hyper (it was actually not) made me "bottle out" for 3 months before trying again.
My TSH, T4 and T3 were not showing me badly hypo, more just sub-clinical Hypo, but I had a lot of Hypo symptoms, hence the reason I tried clearing the RT3 as a solution, and yes, It did "clear" after a bit over 12 weeks, when I suddenly went hyper and had to cut back, but within about 6 months of going back to normal I felt hypothyroid again, (I have chronic pain, a likely source of the problem, and can't therefore lose the source of my problem) so went onto NDT which has generally got things under control since.
Put it this way, I haven't planned on doing it again.