Well,......... you only have two choices......
The recessed portion on the bottom of the heatsink goes directly over the raised end of the zif-socket......
Make sure the thermal pad on the bottom of the aluminum hs is centered directly on top of the processor die ........
Don't tip or rock the hsf to install it, set it directly on top of the cpu, check for centering of the thermal pad,...and gently push down the ends of the retaining clip until they latch ..... the first side is easy, the last one takes considerably more force.
If you can't get it latched w/your fingers, then use the eraser end of a stout pencil ...... or anything else you can think of that will not damage the mb or surrounding components if/when it slips off the clip.
These can be challenging, especially the first time the hsf is installed ..........
good luck, .......take your time, you can damage or break your processor if hsf is not installed correctly ........if possible install the cpu and hsf into the mb before installing the mainboard into the case....
The first time you boot up the system after the hsf install, .......... go into the bios and monitor the cpu temp for a period of time and make sure the cpu temperature remains stable and low enough so you don't fry anything ................!
You may want to check the cpu temp of your old hsf so you can compare before and after temps if you already have your system up and running !