If handy, you can do it. skills to scrape and not to cut yourself! you might need to solder two wires, see below. You, or a friend, normal solder iron, not close or tricky work.
I paid others first round, and did it myself 2nd round with kits I found on eBay.
I have done 3 woofers successfully. The hard part is scraping the old glue off the metal ring, nice and clean to glue new surround to. the important work is getting the voice coil centered, the kits and videos are terrific.
They give you the type of glue you need. importantly it’s drying rate is not too fast: designed to allow placement, refined positioning/centering, and firm enough to hold your chosen position after you let go, and then dry.
two types of repairs,
1. surround only. (outer flexible ring connecting the existing cone to the frame). I did that to my 12" velodyne sub-woofer (rubber surround rotted), cone ok. You remove the old surround from the cone with a chemical they give you. you scrape, the old glue off the metal ring. you glue the new surround inner edge to the cone, and outer edge to the metal ring.
You keep the existing cone and it’s attached voice coil (covered by inner cone which is a dust cap). They have help regarding re-alignment of the voice coil (so it does not rub when moving).
you press the cone in/it springs out, a few times, it centers itself doing this.
or
2. surround and cone. I did that to 2 of my 15" woofers: very old, cloth surrounds.
the cone could have holes (look closely for pin holes), tears, or the material could be old, dried out, needing replacement. They are: new cone with new voiice coil pre-attached, with new surround pre-attached, glue, and separate dust cap.
a. solder two wires from voice coil to speaker terminals.
b. glue pre-assembled cone/surround/voice coil to metal ring. refine alignment. last, glue dust cap over visible voice coil.
I’m very glad I tried it and did it myself, a lot of satisfaction as well as less money, and no shipping out/in cost time.