I cannot find a PPM package of 0.53.

PDF::API2 is a pure perl module. You should be able to install it without problems using the standard get/make/test/install procedure as described in A Guide to Installing Modules. Btw, there is a new version 0.54

update: Mmh. I swear I saw 0.54 when I installed it first via the cpan shell. but after regetting it it says 0.53. Anyway it's still pure perl ;)