It'll depend on what's broken -- could be the hinges, or the hinge mounts, which depending on the model means replacing either the hinges or the base assembly. You'll need to check to see what's broken.
If you need further assistance we'll need the system model (i.e., Inspiron 7331, etc.).
What is the exact system model?
Depending on the warranty and model, we could advise the parts and repair that might be required.
If there is no accidental warranty, then you could contact our team to get a quote for a paid service call - http://dell.to/1vnT6CQ
If you choose to replace the parts yourself, then you could contact a 3rd party Dell parts seller - http://www.parts-people.com/ and order the parts through them.
Also, please click my DELL-username and write me a private conversation with the service tag and your contact details(Name and Email) for case records.
Let us know if you have any other queries.