the bottom of sight glass assembly first requires the safe removal of Bottom mount 537-007-300. I'm using a Right Angle Adjustable wrench to hold lower tank fitting from twisting. 20mm open end wrench to loosen compression nut.
** Caution: observe the mount itself! Make sure it does not twist too! **
Use the 'Hand Grab' method as described in video. Extreme caution taken to prevent damage to both top and bottom sight glass mounts. I believe the whole system needs to be purchased as they (mounts) are custom bent for each tank.
* I really don't reccomebd disturbing this assembly. Please use brush clean out method to address this area. There is no reason to remoce unless the glass is cracked. At which point you can remove every fitting (but don't twist mount tubes). change all gaskets before reassembly.