I don't have the pattern but usually there are 4 markers total for a top down sweater: one between the front and the right sleeve, one between the sleeve and the back, one between the back and the left sleeve and finally one between the sleeve and the front. Are there really 3 or 4 markers for each sleeve on this sweater? Maybe you could quote the row where the markers are inserted and that would help us.
Don't slip the marker off the needle. Just slip it from the left needle to the right. You'll need it for the next increase row.