it is not adviseable to clone during flower but....take the smallest branch you can find and a new razor blade and cut the branch off at the base of the main cola taking care not to leave a big stub if you can and not to nick the main cola. now take the branch and submerge the cut end in a bowl of water, decide how long you want it/ where you will cut, and while submerged you make a 45 degree cut like you would a rose UNDERWATER..thats important that your doing this while the intended cut spot is submerged. then immediately roll in clone gel if available and place in party cup with holes in bottom and filled with pre saturated dirt..this cup goes into a ten gallon tank and covered with plastic wrap with a weak somewhat far away light above...mist twice daily and keep the dirt moist for about two weeks though with practice this will take 7-10 days. as far as cutting off the bud on top, hmmmm, id say you should probably cut it off but ive never tried this so thats not 100 percent. also you may have a lowered success rate since its in flower and with how long it will take to clone off a flowering plant as a noob and how small that plant is anyway, you are honestly better off just telling him grow from seed unless you had some special plant you wanted to preserve.