You haven't mentioned what version of the tool you are using,but if you are in 16.5 or 16.6, you can use the "Symbol Edit" application mode. If your die has the LOCKED property on it, remove it and/or enable locked component editing through the user preferences menu.
Once you've done that, it's as simple as selecting the group of pins and doing an RMB -> Move. You can then rotate them as a group around the reference point of your choice. Doing so will update the symbol definition as well, so your changes willbe recorded in future die text files you export, library symbols you generate, and so forth.