I am looking to merge cells into one for multiple rows of data. I am totally new with excel and have no clue!! Please help

Example:

1 2 3 4 5
jon / doe / test / grade / XXX
jon / doe / test / grade / YYY
jon / doe / test / grade / ZZZ

I need this to become one row, with XXX, YYY, ZZZ in one cell

Example:

1 2 3 4 5
jon / doe / test / grade / XXX, YYY, ZZZ