Vsam file values can be edited only through fileaid.
Take care while changing the value of a key-field as Vsam accepts only in ascending order of key values .So when u want to edit a key field :
Go to file aid (in Edit mode)give ur file name (and copy book)
then edit the key field and give SORT in command line then give SAVE in the command line.
U mean that v can edit the vsam record or not??? if ur query is like this then the answer is yes.. u can just use the update method to do that.. but there are some constraint like the length of the record should not exceed in ESDS, the key value should not be same in KSDS like wise u have some constaints.......