Changing the datatype of a column which is part of a PK

Hi All
I have a table made up of 2 columns as the PK. I am trying to write a script
that changes the datatype of one of the columns which is part of the primary
key. This is what i have tried but i seem not to be getting anywhere:
ALTER TABLE TB1 DROP CONSTRAINT PK_TB1
ALTER COLUMN ACCOUNT VARCHAR(20) NOT NULL
Is there a way to do this? I tried to drop the PKs and then do the changes
and then recreate the PK again. All this gave me errors. Thank you in
advance.> Is there a way to do this? I tried to drop the PKs and then do the changes
> and then recreate the PK again. All this gave me errors.
What does "tried" mean? What errors?
This is the way you do it. You drop the constraints (both primary *and*
foreign key), you change the column, you re-apply the constraints.|||Thank you. It worked.
"Aaron Bertrand [SQL Server MVP]" wrote:

> What does "tried" mean? What errors?
> This is the way you do it. You drop the constraints (both primary *and*
> foreign key), you change the column, you re-apply the constraints.
>
>