There are a couple of ways to do this. But regardless of the method you use I would suggest you first create a cost set call it something like "STD0619" and copy all your costs from standard to this. That way you always have a backup incase you do something wrong you can reset the costs back to what they were before you started to do the rolls. Then run 14.13.13 ro roll just the labor and burden. NOTE make sure you set "Roll-Up LEAD TIME" to NO, otherwise the lead times will all get overridden.
BTW, remember to unfreeze before you do this or it will not be able to reroll the costs.
Another way would be to create another cost set and do the cost roll on that one. (still keep your std0619 as shown above). Then once you are happy with the new costs then copy that cost set to standard. This way lets you do more before you actually affect any costs in the system.