Can somebody give me a rough summary of changing this? Shops are asking $250 to $300. I can't do the work.

If you are getting a quote for a fluid exchange, that may be about right.  It depends on what they are quoting you exactly.  If replacing the filter and just the oil in the pan, that is probably high.  If a full fluid exchange with an exchange machine, that may be right.  That process usually takes around 20 quarts of fluid, and most likely they are using an overpriced synthetic fluid supplied by the retailer of the machine they are using, and another $25-50 for their variety of treatment chemicals.  Most likely what you were quoted is the going rate for the service.
Of bigger concern, is there an issue you are hoping to resolve with this service, or just doing some PM?

If the OP doesn't appreciate your effort, we do JollyZuk. 

I have a video of doing the fluid change by removing the pan on my you tube channel. It called Trash Panda Offroad.