check rf transistor

Hello,
I got one RF board from junk. It has three RF transistors as follows.

MRF136
MRF173
MRF141G

I want to know how to check these transistors. The transistors are soldered in PCB. Is there any special technique used to remove it. What precoutions I should take during removing.

Regards.

Hi,
Remove thr transistor by ensuring the following precautions.
(i) The transistor is not in electrical contact while removing
(ii) Do not apply so much of heat in the body of transistor
(iii) Do not make any physical damage

After removing it, ensure that it is amplifying at the correct rate.
With a transistor analyser, analyse the VI characteristics of the graph.
If these are ok then the transistors are working correctly