How can i fit a top track slider to my tilt and slide patio door?

Hi, I have a tilt and slide patio door. When you tilt it open it is obvious it is not fastened into the top track. Someone told me to get new sliders which i have done but how do you fit these into the top track. Does the track have to be taken down ? Our top track is recessed into the frame on both sides of the patio door so i'm not sure how you would get the track down? HELP !