Changing 3.0 belt tensioner

[imalabil]

I just got back from an oil change at the dealer - $75 with a coupon! - and he told me the serpentine belt tensioner need to be replaced. His price is $445 or so.

Is the a DIY job? Do I need a special tool, if so, does anyone rent it? My X5 is a 2009 3.0. I've seen the You Tube videos but they are all kinda generic.
Crazy thing is I have a brand new fan tool for the E53 I no longer have. I bought it just for the same job on that car.

[bjerols]

I think you need this tool (or something like it) because they stupidly put the AC belt in front of the v-belt on this engine (wtf?):

BMW (N52K) V-BELT INSTALLATION TOOL | KTC Auto Tools


$100 but it would be great if someone has it and rents it out

[bjerols]

actually it may be straight forward:

BMW E90 Drive Belt Replacement | E91, E92, E93 | Pelican Parts DIY Maintenance Article

[imalabil]

Yes, I do NOT have the separate A/C belt. Am wondering how much other stuff needs to be removed to allow access.