Need Code to change data in a populated table

[ppoindexter]

good eveinng everyone
need some help updating a populated table

tblOne
fldA, fldB, fldC

frmBlue
record source tblOne (all fields)

i need to open the form and search for a record in tblOne and change the data in say fldB from apples to oranges (tblFruit is a listing of all choices for fldB)

i think i need some code such as "insert into" but i cant figure it out
all responses appreciated