My instructable required no additional parts, materials, tools, skills, or modifications to the existing strap. It just reconfigures what you already have into what you want.
Step 1: Insert the left-side strap into the left loop
1) Disconnect the two straps from both loops.
2) Insert the left-side strap into the left loop.
Step 2: Insert the right-side strap through the left loop
Insert right-side strap on top of the left-side strap through the loop in the opposite direction as the other strap.
Step 3: Left buckle (part 1)
Insert the right strap through the left buckle (Part 1)
Step 4: Left buckle (part 2)
Insert right strap through the other side of the left buckle.
Step 5: Left buckle (part 3)
Pull the left strap until it is tight against the left buckle.
Step 6: Finish left strap
Slide left sleeve over right strap to complete the left buckle.
Step 7: Right buckle (Part 1)
Loop left strap through right buckle
Step 8: Right buckle (Part 2)
Loop left strap through other side of right buckle
Step 9: Finish right buckle
Finish right buckle
Step 10: New configuation in use