you must do your research
personally
That involves getting a high quality prostate massager, not some cucumber you bought in the grocery store on discount, and insert it anally as the manual tells you too.
Make sure to do it in complete darkness so that you can imagine you're a shota, make high pitched shota noises if you can't. Then imagine the high quality tool you're using to do the deed is the meat of your oppa, call him by name too when you're near orgasm to add romance to the entire situation.