Nice tips Richard!
With the DCX blades the main thing after disabling/unplugging is that one of the ejection arms actually releases the power switch on the blade, turning it off before you start pulling it out. We have the 4 slot ones so the blades are horizontal but the blades are vertical on the 8 slot. There should be a little green power led next to the ejection arm that does the power, it best to release this arm first so power is off before you wiggle things and to lock this arm last once the inserted blade is secure in place (to avoid power while some pins aren't 100%).
I suspect it'll be at the top of the blade on the 8 slots, might be tricky to evenly pull/push the blade in as it's vertical but I imagine you'll have less dangling cables in the way then with the horizontal 4 blade units.
Just make sure the card is in the runner slots at both the top and bottom before pushing in, take a look at both ends when pulling the old card out to get an idea of how it fits. Make sure pressure is evenly applied on both arms and as mentioned once all the way in lock the powering arm last.
I have had occasion when the blade didn't power up, give it a minute and check the lights and diagnostics to see if it's recognised. If it isn't then you may have to try again, release the powering arm first then the other and slide out a couple of inches, check alignment and go again. Might need a firm but gentle push to get all the connections in okay. The arms act as levers to help even the pressure during the pin connection part.
Oh and make sure to remove the pin covers on the new blade before inserting, nearly missed that once.
