The solution I'm using isn't pretty, but it works. Here's what I do:
Create a script of all the stored procedures as "create to" file or clipboard. Once it's finished, I put the resulting script in a text editor (like notepad). Once there, I do a find and replace to change the "create" statements to "alter". Be carefull not to do a replace all though! If you do, it'll break any temp tables by changing the "create table" into an "alter table".
Hope this helps.
James