Following scripts will take care to change schema owner
Mk_altr_proc_owner.sql ( copy past this SQL statement)
SELECT ' alter procedure '||rtrim(nspname)||'.'||ltrim( proname )||' owner to targetschema;'
Maybe using quote_ident to prevent, unlikely as it may be, SQL injection issues. The trims seem likely to be unnecessary - catalog contents should be clean.
The script output file is nice to check one's works I guess. But if you are going to use psql there is the \gexec meta-command that makes this even easier.