regular expression question

I am new to regular expressions and use nintex workflow manager which has a regular expression tool inside of it. The options are

1) extract
 2) split
 3) check match
 3) replace

I have the line

 i:0#.w|instructional\username

and I want to remove the
 i:0#.w|
and just be left with the instructional\username
i have used the "replace text" with blank to get rid of unwanted text.
when i do this i am left with
|instructional\douwin01
IT does not get the "|" how do i get it all?
Thank you for your help.