Need to redownload purchased product

I recently deleted the 737NGX w/out winglets set from my PMDG 737NGX set.   My plan was to save space by keeping the 737-800 & -900 only with the winglets.  When I opened FSX and went to 'Select Aircraft' I noticed my entire PMDG download was gone.  How do I a) Redownload the 737 NGX from the PMDG site asa my download URL has expired? or b) Get the winglets versions to show when I go to the 'Select Aircraft'?  Thanks.