System with two different time signatures simultaneously

I have a score (8 staves) where one instrument is written in 6/8 while the rest is in 2/4. This is not a terribly rare occurrence but I have been unable to find out from the handbook how to achieve that in Musescore (the composer worked with ink and pen; for him it was easy). Can anybody help me with this?

I can of course solve the problem by changing the meter to 2/4 everywhere and using triplets. But It would be nice to typeset it as the composer wrote it.