- unhide the gear sheet (Format > sheet > unhide > gear)
- copy the whole line of an existing item
in the correct gear area (helms go with other helms) by right clicking the line number before the first cell and selecting copy
- insert the copied line
in the middle of the block (don't copy it at the beginning or the end of the particular section) by right clicking the space between two line numbers on the left and selecting insert copied cells.
- modify
only the name, stats, sockets, speed/dps for weapons, socket bonuses (abbreviated as s.agi for agility, etc...) and drop zone, DONT TOUCH ANY FORMULAS