Using the PCG Library
The PCG library provides access any easy way to use PCG generators. You have several options, all available for download.
C Minimal Library
This is the smallest code. If you want to look at the code, this is probably a not-so-intimidating starting point.
You can use it as a drop-in replacement for rand or rand_r (substituting pcg32_random for rand, and UINT32_MAX for RAND_MAX because the random function always produces a uniformly distributed full-range 32-bit unsigned integer).
This version of the code is the canonical version from which all others are derived, and is the most featureful and easiest to use. If you can use C++ in your project, you should probably use this version of the library.
It is provided as a header-only C++ library, modeled after the C++11 random-number facility. You can use it as a drop-in replacement for any C++11 random number generator, although it provides a number of facilities that go beyond those generators.
C Complete Library
This version of the code provides most of the features of the C++ library (including a full suite of PCG-family generators). It's provided on the basis that some people cannot use C.