A user must have Development Full role to associate Contact Attributes to contacts. 

1. Navigate to the list of Contacts (Development>Contacts) 
2. Select contacts by clicking on checkboxes in each row.
3. Select Multiaction -> Add Contact Attributes
4. Repeat the steps performed for Associating Contact Attributes to Contact

The new attribute association will appear below.

See also
PCR Educator K-12 School Information System is an online database engineered for independent and private schools to deliver the highest level of flexibility, unique experience, transparent communication and customized design. Being a complete cloud-based solution, PCR Educator system guarantees convenient access anytime, anywhere.