in this https://joyofsatan.org/www.angelfire.com/empire/serpentis666/Fighting_Back.html..Can even beginner like me who is in the middle of 40 day power meditation do all this?
Yes, you can. I am also in the middle of the 40 day program and have done a bunch of other rituals and RTRs outside of the program. Experiment and try new things. As you advance in the program you'll also get better at other workings.
Also, the link is broken, I think this is the correct one:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/Fighting_Back.html