Here is some more info:
1. The format the files are in is as follows part1.part2.part3.part4.extension
part 1 = various words (sometimes just one, no numbers) separated by varying number of dots. No spaces between dots and/or words.
part 2 = is always 6 symbols long with mixture of letters and numbers. the numbers at the end increment by one going down the list
part 3 = always varies in terms of words, numbers, symbols and dots separating them. still no spaces between them.
part 4 = virtually always a mixture of letters, symbols and dots. numbers are rare so if they're present i can rename manually. but for each set of files that need to be renamed those letters, symbols and dots are always in the same sequence.
Part 3 is the one that needs to be removed
Of course, the cases of letters need to be preserved during renaming
Cheers for the help!