To complete a throw escape you will need to press

and

at the same time just as you are being grabbed.
An easy way to do this -
1 - Head into Offline mode / Practice, Select your fighter as King (any will do but I used him for this solution)
2 - Select your opponent as Jin (any will do but I used him for this solution)
3 - Once in the game press

to bring up the menu
4 - Select "Mode Select" and change it to Defensive Training
5 - In the next option it will say "CPU Setting 1", Go onto that and select Command list go down to move number 070/078 called Over the shoulder reverse and select it
6 - Now scroll down to the option "Interval" and change it to Normal
7 - Press

to exit with settings
8 - At the bottom it should say

+

Start, Do this and Jin will start to try and grab you
9 - Rapidly press

and

at the same to to perform a throw escape do this 9 more times.
( you will see when it has been performed correctly because King will pull away then punch Jin twice sending him flying away.
He will catch you here and there but no worries this trophy will be yours very quicly.
Hope this has helped you!