Can I replace this myself?

You can always stop at the dealers parts dept. If the price is outrageous then go elsewhere. One option is the junkyard.

 

Check with dealer parts dept

 

That's usually the way it works, which is why when you go to parts.toyota.com there are diagrams.



Looks like you're wanting the part there that is called out as 53866, which is seal, front fender to cowl side, right.

 

That's a little alarming; parked outside a lot?

I think you'd have to partially remove the fender. Info's not in Repair Manual, as far as I can see. I believe there's a separate manual for bodywork?

Might be simple enough: I see there's one bolt up at top of front/right door jamb, and several in the seam (in engine bay) along top of the fender.

 

Sometimes it's helpful to just go buy the part (just $10 at the dealer) and look at it closely, which will sometimes suggest what's involved in replacing it.

 

I'd be really surprised if it was that cheap at a dealer.
IIRC a single replacement roof rack rubber filler strip was something like $75......and that was maybe 5 years ago.

 

If I hadn't just linked to it in the OP's other thread, I probably would have hedged more.