Unload kayak

Any tips on how to install transport wheels on boat ramp by myself?

It all depends on the wheels.  If you have a scupper cart just tip the boat on its side and put the wheels under it.  For other carts you can lift the stern and slide the cart under. 
Landing is even easier just slip the cart in place when the stern is still floating. 

If you have a full size Wheelez its easy.  Pull the boat out of the water up on the ramp STERN first.  This lets you keep the bow afloat while clearing the stern of the water.  Pull out the kickstand and orient the Wheelez beside the boat and just behind the seating position with the kickstand forward and the cart angled so it is pointing toward the bow.  Lift the stern and place onto the cart.  Use straps or bungees to secure.

You may also be able to put the cart on the boat while he boat is still on your vehicle, depending on the shape of the vehicle and your carriers.  On my truck with the lumber rack, I can scoot the kayak backwards until just before the tipping point, and bungee the Wheelez to the kayak while it is still on the rack.