I am going to change upper and lower A frames on my 2004 Ram 2500 soon. Am I gonna need a spring compressor for this?

 

You can rent it from O'Reilly's, if needed.

It is not necessary to have the spring compressor. If your truck is up high enough on jack stands, you can remove the tire, then loosen the top and bottom ball joint nuts, knock the tapers loose, use a floor jack to slightly compress the spring by lifting up the bottom control arm, remove the ball joint at the top control arm, remove the bottom and steering knuckle, then drop the bottom control arm down all the way to completely relieve the spring. Best to find a video on YouTube to walk you thru it.