Hello srinivas rao,
Change of Planner Groups in several equipments in mass:
If your system is EHP2 and above, you have a Carryout Mass change option in GoTo in the menubar, through which you should be able to do. If your system is below EHP2, then you need to do it by LSMW which will be a very simple task for this job.
Plans
You need to change the Planner Groups of all plans created on these Equipments. It is a job of mass change of Plans,Tcode MCH01 is the answer.
Best of luck
KJogeswaraRao