rename -n 's/.{5}(.*)/$1/' *
The -n is for simulating; remove it to get the actual result.
-n
you can use the following command when you are in the folder where you want to make the renaming:
rename -n -v 's/^(.{5})//' *
-n is for no action and -v to show what will be the changes. if you are satisfied with the results you can remove both of them
-v
rename 's/^(.{5})//' *
Something like this should work:
for x in *; do echo mv $x `echo $x | cut -c 5-`done
Note that this could be destructive, so run it this way first, and then remove the leading echo once you're confident that it does what you want.
echo