Changing bulb in a pinhole downlight

First, make sure the fixture is switched off.

Using a small piece of cloth, to protect your fingers in case the bulb breaks, grab the bulb firmly near the base, and rock it slightly back and forth (left to right), so that you are alternately pulling on one pin, then the other. Once the pins start to move you will probably be able to pull it straight out.

If the bulb does break, you should be able to remove the remaining parts with a pair of needle-nose pliers; be sure to apply the force in the direction the pins are pointing so that you don't break them off.

Your fixtures should have a maximum thermal power rating, as long as you don't exceed that with your bulbs, there should be no safety problem from the fixture.

If you were to use light bulbs with electronics such as CFL or LED, you would also need to insure you don't exceed their temperature ratings. CFLs, for example, are usually made to be used in a "base down" position so the heat will rise and dissipate. A CFL used in a recessed fixture will be in a "base up" situation where the electronics will be hotter.

Have you considered using a PAR E27? I don't know your fitting size but a PAR20, 30, or 38 will probably work out better than trying to adapt a GU10.