How to replace strings in Powershell… collection of web resources:

http://technet.microsoft.com/en-us/library/ee692804.aspx

http://blogs.technet.com/b/heyscriptingguy/archive/2011/09/21/two-simple-powershell-methods-to-remove-the-last-letter-of-a-string.aspx

http://lucky-le-koala.over-blog.com/article-microsoft-powershell-chaine-de-caracteres-50239043.html