Left side curtain airbag replacement

[Lost puppy]

New to the group. I have a 2006 X5 3.0. Earlier this year when we had the heavy rains I was on the freeway and something pierced my tire and it sent me sliding into the the centre concrete divider long story short
Both airbags on the driver side have deployed I just replaced the one in the door that was no problem I need to replace the side curtain airbag up in the headliner. Is this something I can do myself or do I need to pay the dealer $3,000 which I was quoted for replacement?. I was wondering if anybody has experienced replacing their side curtain airbag and if so is there's anything special I should know about or whatever And yes I did order the Bentley service manual it is on its way. If anybody can help me out I'd really appreciate it thanks Kendall