If you can do the exchange without removing the lens pair from the lens panel, it will probably work. Each lens has a slightly different focal length, and the pairs have to be matched. Sometimes this is done with shims between the front elements and the lens panel. There is an argument to switch the elements of both taking and viewing lenses, but if you do it, I'd try the critical one and test the result carefully to see that resolution is what you expect, and that the focus remains in sync.
It's ultimately your call. Do get hold of the right lens wrenches before you start. There is always a risk of damage doing this sort of thing. You hear many tales of people doing front element swaps on these lenses. You don't hear about failures very often!