I am using Versions (Mac OS X SVN software) and created a branch labeled 3.0
I would like to take everything up to revision 144 from our Trunk, and basically do it in the 3.0 branch.
I do not know how I should do this.
You will have to use the command svn copy.
svn copy
svn copy my_repo/trunk -r 144 my_repo/branches/3.0
or
svn copy ^/trunk -r 144 ^/branches/3.0
where ^/is the shortcut to the remote URL.
^/
check the documentation here
Try it...
$ svn copy -r 144 URL/trunk URL/branches/Rev3.0