How do I put the handle back on my faucet D223154?

There is a set screw on the handle usually has a tab over it make sure the handle is properly flush to the base( i always loosten set screw take handle off make sure flat side of stem ( what handle slides over) is where the set screw tightens against . put the handle back on make sure it is as far towards the base of the faucet then take your hex wrench and tighten it down

you may have to use a little force gently pry under the handle be extremely careful not to break handle i usually take a piece of wood to put up against faucet or whatever and then tap faucet with hammer then start prying back side with a screwdriver or small breaker bar use your hand to try to wiggle the handle

Youll need to seperate the valve stem from the body so you can see if the screw has come off and re-attach.

remove stem, turn it half a turn in either direction (180deg.) replace stem and your good to go

1st put the DOME cap on by rotating it 180 degrees, to go OVER the white plastic gasket, then press on. Then you have to get that plastic square knob inside the dome, in a downward postition, thus TURNING the WATER ON, to work the handle back in place. Put the set screw on with an (tiny) allen stick wrenchy thingy.

I believe there is a set screw behind the hot and cold symbol on handle. remove symbol to remove set screw for handle. shut off water supply to faucet. after handle is off, then you can remove inside parts. use a pair of pliers to remove retaining ring under handle. then remove faucet spout by pulling it up. replace all bad O rings then put back together. have a good day !!

the whole faucet is bad it has an internal leak replace the whole thing

Here's the solution from Delta:
On a two-handle kitchen or lavatory faucet, if the handles rotate in the wrong direction, simply rotate the right stem stop assembly 180 degrees. This will change the rotation of the handle to the other direction.

Here is the owners manual for your faucet that will guide you through putting the handle back on. Good luck!
http://www.moen.com/shared/pdf/instruction_sheets/INS060B.pdf

Check out this webpage:

http://www.americanstandard-us.com/assets/documents/amstd/parts/Parts_599.pdf