Another video showing the process of hooking up the shifter to the derailleur and adjusting:    • How To Install And Adjust A Shimano 7...  
Installing a new Shimano model SL M310 7R shifter onto an older Diamond Back mountain bike. The bike had an older 200GS 7 speed group with the older rapid fire type shifter. Typically I'll refurbish the shifter, but in this case, the bicycle owner wanted to replace the shifter with newer style replacement.