I am looking for changing the datatype of a field from nvchar(20) to nvchar(MAX), but it retains the below message.

my questions here:
Deleting the index will affect on the data?
Can I restore the index after deleting it and changing the data type?
Is The index in the screenshot below the only index that will be deleted?

I will be very appreciated for any help :)

Best,
Lubna

[![enter image description here](https://i.stack.imgur.com/aAhdN.png)](https://i.stack.imgur.com/aAhdN.png)