MrSP has provided a useful description of the solution at http://www.playstationtrophies.org/forum/quell-memento/200328-guiding-spirit-4-3-gem.html

But to save you time, here's the solution:

RU

[switch to second, rightmost bubble] LDLDLD

[switch back to first bubble] DLURUU [this destroys the first bubble and the red drop]

RRLRLRLR