Universal use of drive shaft 2002 to 2003

Could you take a picture of the two parts? The 2002 and 2003 used the same drive lines unless you have a part from a long wheel base going into a short box or a 4 cylinder with a manual transmission. How did the shaft fail? U-Joint or?

Okay. The failure is that the flange yoke on the 2003 failed and that let the U-Joint come apart. You are going to need a few more parts. First a new rear flange yoke like the first picture below and a new U-Joint like the second picture to replace the scrap one in your replacement shaft. Then you just need to unbolt the broken yoke from your truck. Remove the bad joint from the replacement shaft, then assemble all the parts to be able to reinstall it.
This shows how that rear yoke is bolted on. To start with you will want to mark the rear ends flange area so that you can install the replacement part so the U joint is in the same position it is now. See the edited one of yours. The orange are the bolts. You want to make the piece that flange bolts onto so the cap on the new U-Joint is in that same spot.
https://www.2carpros.com/articles/how-to-remove-a-drive-shaft

Now with that off clean the mating surfaces where the bolts go so there is no dirt or rust.
Getting the new yoke may take a bit of work, most of the chain parts stores likely wont have it or even be able to get it. NAPA might be able to or visit a salvage yard for one.

Now you need to replace the U-Joint in the end of the shaft and install the new yoke onto it.
Here are a few videos on that job. As ETCG says, you can usually get a U-Joint press at the parts store as a loaner tool.
https://www.youtube.com/watch?v=c2cPZMj6Gvw
https://www.youtube.com/watch?v=8VQQdrUi9wA
https://www.youtube.com/watch?v=uewFHe6H2Tw

If you have the two piece rear shaft and only have the rear section, you will want to get a different shaft that is complete, they are balanced as a unit so you cannot mix and match the two halves without causing a lot of vibration.

That is a common GM part. Used on pretty much every S series. The piece in the picture isn't a splined part, it is a bolt on part that attaches to the yoke that is attached to the pinion gear. Remove the 4 bolts and it's off, you don't need to touch the adapter splined yoke on the differential.

There are millions of those yokes in salvage yards all over the world. If you want a new part you would need to look at places that sell 4WD parts and things like lift kits and driveline upgrades for one that is a bolt on. However for stock parts any salvage yard with Chevy S-10, Blazers, Olds Bravada, GMC S-15 or Jimmy trucks will have that bolt on yoke. I know of no splined yoke that will bolt on though. Just call a few salvage yards and they should have at least a half dozen on hand.