Golang mutate a struct's field one by one using reflect

I have a struct like this:

type User struct {
    Name   string
    UID    int
    Bio    string
}

I have a given instantiated struct, and I want to loop through the fields in that object and modify them one by one.

This is what I have so far

user := User{
    Name: "Test",
    UID:  1,
    Bio:  "Test bio",
}

reflectVal := reflect.ValueOf(user)
numFields := reflectVal.NumField()

for i := 0; i < numFields; i++ {
    fieldType := reflect.TypeOf(reflectVal.Field(i))
    reflectVal.Field(i).Set(reflect.Zero(fieldType))
    ...
}

But I'm getting this error:

panic: reflect: reflect.Value.SetString using unaddressable value

Is there a way to do this?