Double glazed window (the manipulate locking system fell apart)? how do I replace a new knob locking system.

how do I replace a new knob locking system.
Answers:    contact the firm that installed the windows and if still beneath guarantee it will be fixed free of charge otherwise the charge will be - the call out charge plus parts plus chore..
err... get a proffessional?......... or scour online or ask a worker at ur local home improvement center (lowes, homedepot, ace, osh etc