U-Up D-Down R-Right L-Left F-Front B-Back
F means turn the F face clockwise
F' means turn the F' face counter clockwise
this is the face's technical clockwise and counterclockwise, not how it looks to u
Um... Pretend the side facing you (F) is red and the side on the right (R) is blue and the side on the left (L) is green, the top (U) is white and the back (B) is orange
Now find the red/blue edge piece on the D face (down) if the red side is on the D face, twist the bottom so that it is at the DB place
If the blue side is on the D face, literally turn the cube so that blue is the new F face and red is L and put the piece at the DB place
now, do F' D' F D L D L' if you need it on the FL place
and F D F' D' R' D' R if you need it on the FR place
You may need to do the aforementioned moves to get the piece onto the bottom in the first place....