I am a first timer user of a drill and didn't use the proper drill bits. I removed the chuck and put the drill bit where the chuck is located and now the drill bit is obviously stuck. Any suggestions on how I get it out?
find a screw that fits the stuck bit and also fits into the hexagonal hole.
put a small amount of superglue in the recess of the screw.
holding the screw verticaly so that the glue does not spill into the drill press the drill down over the screw so that the bit fits into the recess.
hold this awkward pose for 10 seconds then pull the screw out. the bit should now be stuck to the screw and come out fairly easily.
You've already discovered directions for partial disassembly of your drill, continue with those instructions to disassemble the rest and get the bit out of there.
If you somehow just manhandled the chuck off and didn't follow instructions, the web is flush with OEM & aftermarket sellers of replacement/repair parts and 99% of them will include schematic drawings of the drill. You will also find a wide variety of videos on YouTube that will instruct you on disassembly. I'd suggest watching 5 or 6 to find the more "professional" looking ones and follow them. If the video starts out with the presenter saying something like, "well, I messed up my drill, let's see if we can figure out how to take it apart...", that's probably not one you want to trust. If it's a guy in a clean room with a clear workbench, good lighting and good camera work, it's probably someone who has done this several times and has a group of engineers who have figured out exactly how it comes apart & goes back together, and will talk you through the exact driver sizes & other tools you need for each step.