Translation:You need to press the switch with your fourth toes.
If it helps to remember what toe is what, think three little piggies, and the sounds the syllable makes transliterated into klingon.
market home roast none then the last one blew its top (before going wee-wee-wee all the way home).
The gag with fingers is a whole different kettle of fish unless, so I'm told, you are familiar with a lake system in New York State.
The last one "cried" (Qay') wee wee wee.
And yes, the Finger Lakes -- though not in any obvious east-to-west or west-to-east order:
- Sen (Seneca)
- SIq (Skaneateles)
- qay (Cayuga)
- qew (Keuka)
- qan (Canandaigua)
I'm not sure where rIl comes from, at least in the sense "use the thumb".
(The sense "blow into musical instrument" is probably from gheb rIl "he blows (into) the horn" = Gabriel.)
Perhaps because the speaker is speaking to multiple people (bo-), so there will be multiple toes. (Though each actor might use just one of their two fourth toes.)
As for the dexterity of Klingon extremities:
Klingon toes have more dexterity than human toes, though not as much a Klingon or human fingers. To a degree surprising to humans, Klingons can control each toe independently.
When speaking to a group, it would be more formally correct to refer the singular body parts of each in the plural. One would say formally to a group, for instance, Raise your right hands, not Raise your right hand. Informally, speakers switch from addressing an entire group to addressing each individual in that group separately all the time.