Remove the 4 bolts under your column and carefully drop the assembly.
The wheel will fall just enough to expose a white, gray, black or blue plastic mechanism which connects to a rod up your column.
You can search for the column diagram for the year of your truck.
The switches get dirt into the slider and stick open or break from dried out plastic.
Here's a non-tilt in black:
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Make certain the connector matches the old unit and tilt configuration is the one you need or the parts store might not take it back. The slots are for adjustment. Try to locate it where it was. Lot's of pics...
I have successfully pulled the old unit apart and lubed the ball bearings and terminals internally, in order to get the truck up and running. They might go flying though... (Last resort only.)
There's nothing like a new Standard Motor Switch, so buy the good stuff, not the junk.
Using a gob of dielectric grease on the electrical connector and where the rod slides the internals, before you put it back. This will lube and seal your ignition switch for a good long while. The rod up the column has to insert and drive the switch. Take your time and make certain the high beam switch is adjusted correctly and functions properly before you button everything up. It is easy to get the high beam rod flipped and then it doesn't work, so take a few pictures before you get into it.
The steel edges will be sharp. Try not to give blood.
I have made this repair in the dead of summer... find some shade.
If the key still gives you a tough time, there's a gear made of plastic inside your column which drives the rod.
If it's broken or full of dirt, the OEM cylinder and a new drive gear might be next.
Have fun!