Today when I was about to take off, suddenly a big poof with a lot of steam and coolant on the road. Stopped og got road rescue to take me home.

At home I investigated and found a busted coolant hose behind the wheel well RH.

Any idea what this is and how hard is it to change?

Click image to enlarge

Click image to enlarge

Click image to enlarge

Click image to enlarge

It's hard to see from the photo which pipe it is that has split. But all in that area are easy to replace.  2010 RR Autobiography 5.0 SC
2020 F-Pace SVR 5.0 SC
2018 RRS HSE Dynamic 3.0
2014 Disco XXV
2011 Disco 3.0
2009 RRS HST V8

One step closer.
Think it's actually the air condition hose to condenser that burst. Looking at the color it matches the R22 refrigerant (light/neon green).

Yes that one is defiantly the AC hose. It leads from the AC rad to the compressor. 2010 RR Autobiography 5.0 SC
2020 F-Pace SVR 5.0 SC
2018 RRS HSE Dynamic 3.0
2014 Disco XXV
2011 Disco 3.0
2009 RRS HST V8

Then the big question; is it worth trying to replace myself...?
Can't find much info online or in the workshop manual ----------------
2012 - L322 Westminster
QRV @ LA2VSA / DA1AA

It's a doddle of a job to replace, just a bolt on either end and from memory a fixing bracket at the Bottom of the engine. But you will need to re-gas afterwards. 2010 RR Autobiography 5.0 SC
2020 F-Pace SVR 5.0 SC
2018 RRS HSE Dynamic 3.0
2014 Disco XXV
2011 Disco 3.0
2009 RRS HST V8

Good. Hopefully I'm able to get that part quickly. Not the most common car in Norway. ----------------
2012 - L322 Westminster
QRV @ LA2VSA / DA1AA

If there are any other hoses on that system it would be worth replacing at the same time, as 13 years on a hose, is well past its useful life. 2018 SE SDV8 4.4 Byron Blue