Assembly

I used peg and hole joints
- Getting a good jig makes these much easier and neater
Drill and peg (don't glue) D to slides (pieces H and I)
Follow by drilling and pegging pieces by G, C and E in that order
Drill and peg pieces A and F to sides and each other
Finally piece B was dilled and pegged using pilot holes drilled in from the back to mark positions of joints to A and E.
Assemble using straps round cabinet to hold joints tight
Test fit and mount brackets
Glue when satisfied with fit!
Reinfoce with screws if required

I used peg and hole joints