wanna apply one or two tracks HELP

Hey all i wanna apply like one or two tracks to the back of my hair to make it look about 4 inches longer and thicker, the hair in the back of my head is about 5 inches below my shoulder and i wanna apply like 2 tracks in the back (where my ears are) to make it a little bit longer yeat thicker, what method should i use? i dont want it to last months maybe like around 2 weeks, would glue to the trick? and if i use glue do i apply the weft/track right on my scalp where the roots are or like on the hair itself like cm. below the roots? thanks a bunch!!!!

yeah I agree with AstroPuffs since you only want to add in a couple of rows for a little length and thickness the clips would be a great and easy alternative to glue/bonding.