You might be able to unbolt the seats from the '03 and bolt them right onto the '05 tracks. If you're lucky, the bracket that holds the seat switches from the '05 seats' frames might screw right onto the '03 frames. Then you can just cut the '03 seat cover and pop the switch in. If it were me, that's what I would try first.
However, once the seats are out, it's really not that hard to replace the covers. But the covers have to be an
exact match, and that might not happen going from an '03 to an '05. If you want to try this, you also might want to invest in some hog-ring pliers and hog rings.
When I recently redid the interior of my truck (had to replace the blend doors, so while everything was out...) I bought new leather seat covers from u.s.autoseatcover on ebay back in February of 2022. They only had the bottoms I needed on ebay, but I called and was able to order the seat backs directly. The leather color is really close to the original and the texture is smooth; the factory leather had a "pebble" surface to it.
I must say, I was very impressed with the customer service from u.s.autoseatcover. Getting the covers made right was more of a saga than the install, hence my comments on customer service. I also changed out the driver side foam with the one from Geno's.
In my case, the seat backs I received were ordered with "suede inserts" (Laramie truck) and embroidered sheep's head. They came with cheesy cloth inserts. Also, since the order for the bottoms (ebay) and the order for the backs (telephone) were separate, they were originally cut from different bolts, so the color did not exactly match. I called them back and told them I did not like the texture of the cloth "suede;" they said they didn't have any real suede leather, but offered to re-do them with regular leather if I wanted, so I took them up on that and had them put in a black insert since I was putting in a new radio and the new center panel bezel was black, too. But they would have done the panel in the same color as the rest of the cover if I wanted. They also offered to re-embroider the sheep's head, which was very well done on the first set, but I passed. They also asked me to send one of the replacement bottoms back so they could match the bolt to the one used for the bottoms. The only minor issue remaining with the backs is that the foam padding on the top where the headrests attach isn't as thick as stock, so the plastic clips stand a little proud as you can see in the attached photo. If I cared I could add a 1/2 inch of foam up there and nobody would ever know, but it just wasn't that big a deal for me.
As to the seat bottoms, the clips (service manual calls them "j-straps") were not the right sizes, nor in the right places, they were clearly meant for a different frame. So I called and sent photos; they asked me to send the bottoms back, along with my factory seat covers. They re-made them matching the bolt and reusing some of the plastic clips from the factory covers. They fit perfectly.
In all the back and forth, the people at u.s.autoseatcover were very approachable and made it right. I would be comfortable doing business with them again. And with the new radio, new carpet and redone front seats, my truck is like new on the inside. Now I just need to get it repainted so it will look as good on the outside.
Tired driver's seat
Cheesy cloth "suede" insert with logo
Re-covered front seats