Lower Tailgate Wont Open

Hi all! Im having trouble opening the lower tailgate on my L322.

The top half opens no bother with the key fob etc but the lower half doesn't open at all. I've tried the button on the top of the tailgate and even managed to remove the inner tailgate cover to check the switch etc but its not working. I remember when I purchased the car the previous owner said he had trouble from time to time but he managed to open it by sliding a knife down he inside and pressing the latch down.

Does anyone have a "how to" or a brief description on how to do it as I need to load the car up over the weekend and it would be helpful if the tailgate actually opened.

Thanks

You can release the 2 catches manually where the top edge of the lower tailgate meets the light run a finger down the gap between the body and the tailgate there's s tab either push it or lift it can't remember which , and it resleases the catch would post a pic but my car is not in the same country

It is shown in the manual how to open the upper and lower tailgate after a battery failure

There is a small relay in the rear fusebox which controls the two solenoids in the lower tailgate....check this hasn't burnt out.

My lower tailgate refused to open on the button too....I checked this relay and replaced with a new one and it still didn't work...the button was fine, and the 'open' signal was getting to the BCU (wait for the interior lights to go out then press the button, if the lights come back on, the BCU knows the button has been pressed and has asked the LCM to turn the lights on....but it still wouldn't unlock)

So I bridged this relay with an momentary switch To fire the lock solenoids....so far it works....Now I have diagnostic capability back after the blown HID lamp incident...I will replace the relay and see if it works now....if not, I'll go back to the momentary switch again until I can figure this out....

I did change out my solenoids, did I not do a How To for it??