It is possible - Air box and carb out, right hand rear shock off, breather tube and connector at back of mag cover off. Feed the exhaust in from the rear (side) so the exhaust front end sort of loops around the right hand part of the frame behind the engine (triangular part with the footrests) so it can hang hooked on to this part of the frame resting on the back of the mag cover. Now feed the exhaust in to position clockwise so the front part just sneaks through the gap between the barrell and frame (it should just fit through but is very tight on clearance). Now the main body of the exhaust should be above the head but will be rotated as the front part will be down beside the right of the engine instead of in front. Ease the whole exhaust forward and rotate until the part that goes into the barrell can just pass in front of the front tubes. Its now in position if you are lucky.