OK...you can reach the lever that the cable pulls through the handhold hole on the left side of the tail cover. Using a long thin flat blade screwdriver you can push the end of the lever the cable is hooked into towards he right side of the bike and un-latch the seat....at least with my carbon fiber tail....I presume the stock plastic tail has the same opening...maybe not.
I took some phone photos. They came out like crap....but here they are. One shows the screwdriver blade pushing the lever. The other shows the hand hold opening in the tail section and the daylight where the seat latch is hiding.
Well I nearly missed it just wishing Sophia my 910S BRUTALE
A happy birthday built in early 2005 purchased in Feb 2006 ive had her 15 yrs , 13 absolute wonderfull yrs
Still haven't ridden her much in the past yr feeling guilty