You can use the projadd and projmod project database administration commands to edit project attributes.
The –K option specifies a replacement list of attributes. Attributes are delimited by semicolons (;). If the –K option is used with the –a option, the attribute or attribute value is added. If the –K option is used with the –r option, the attribute or attribute value is removed. If the –K option is used with the –s option, the attribute or attribute value is substituted.