Follow this post to use multi line find and replace. I find this especially helpful when editing header parts of my scripts on Github or batch editing of any kind for that matter.
Download and install Notepad Plus Plus.
Download and install Plugin Manager (UNI for x32 and x64 for x64, you will want the 32 bit even if you are on 64bit machine)
Add the Toolbucket Plugin
NOTE: For both of these, you just copy the DLL’s directly into the NPP Plugins directory at C:\Program Files (x86)\Notepad++\plugins
Also, restart NPP if you had it open.
Open all your PS1 Files and drag them to a blank NPP window
Do the actual MultiLine Find and Replace by going to Plugins => Toolbucket => MultiLine Find and Replace (Alt+Shift+F)