Red launch controller issues.

Hi guys,

I've googling on controller repairs and looking at videos about it, yet I still have some questions about my red controller that I bought with my original PS4 way back on launch day.

Basically, the controller still functions, aka I can do everything in game. But it has some issues.

The bottom right trigger doesn't stick, but sometimes when I press it, the game keeps thinking I'm holding the trigger down. So it's not releasing the button, even with the trigger released. I'm assuming something internally is getting stuck?

The left stick works fine, but it does not rotate smoothly anymore. There is like a "clunk" in it when I'm in the bottom left corner. Normally if you do a couple of 360s on your stick, it's super smooth. But with this stick there are like little hickups/jumps when I get in the bottom left. I'm assuming this is probably something broken inside.

I know I have to open it up, but should I already order some parts before I do this? The left thumb stick also had some rips in the rubber rim, so I was wondering if I should just order replacements sticks before opening it up.

Many thanks in advance for any help/tips!