Removing the gutters makes it much easier to get up to the fascia board and to cut through it. If you try to do it without removing the gutters, you'll have to be very careful not to damage them or else you'll have to replace them as well. Additionally, it will be harder to properly seal the new fascia board against the roof if you don't remove the gutters.

Yes. It is possible to replace fascia board without removing gutters, but it is a more difficult and time-consuming process. First, the gutter must be detached from the fascia board. Then, the old fascia board must be cut away and the new fascia board must be attached using nails or screws. Finally, the gutter can be reattached to the new fascia board.