Hey pablojavier,
in my opinion NL100 is still beatable with standard SHC, but if you want to start loosening up your range, I suggest you do as dandycal said, first start adding AQ and TT to EP openraises and AJ and 88 to MP, but I think that's of lesser importance. You should learn how to isolate a fish when you see a good spot and how to steal/resteal correct according to villain's stats. And use a squeeze or two when the situation is right. And to learn all this I think it's best to look for some xarry2's videos and his coachings.
Another thing, if you start loosening up your ranges it's wise to also start using smaller raises like 3-3.5BB instead of 4, so you don't lose too much when people will 3-bet you preflop and you have to fold.
Btw, you're english is completely understandable. 
Regards,
burek2000