you have two pies coimnig off the top of the inlet manifold, one goes to the fuel pressure reg ( round brass thing) the other goes into a t piece. the pipe coming off the t piece goes into the n249 valve. this valve also has other pipe going in the back. and one coming out of it to the dv. remove the pipe going to the dv at the n249 and remove the pipe going to the 249 from the t piece join these with conetcor in line sort. thats the first bit, this way saves removing pipes from t peice i brok my t pice trying to this lol.
next bit is to run a pipe from the back of the non return valve, this is located just after the t piece, this valve has a pipe going into a right angle conector remove the pipe from the right angle conector and get some new vac hose and another connector, then you will see another valve like the 249 at the back of the engine bay. remove the hose that joines into the frame of pipe that connects to the vac chamber. and attach hose from the connetor you installed on to this
sounds complicated but if you look at the pics of my red hosing you will se what im meaning