It may not be any "easier" than Brown's proof, but the work of people like <a href="http://www-fourier.ujf-grenoble.fr/~sergerar/Papers/">Francis Sergeraert</a> and others has created a nice conceptual framework for these types of questions. See especially the paper, <a href="http://www-fourier.ujf-grenoble.fr/~sergerar/Papers/AAECC-Effective-Homotopy-of-Fibrations.pdf">Effective homotopy of fibrations</a> by Romero and Sergeraert. They have also implemented their algorithms in Kenzo. See also <a href="https://idus.us.es/bitstream/handle/11441/125882/1/An%20algorithm%20computing%20homotopy%20groups.pdf?sequence=1">An algorithm computing homotopy groups</a> by Pedro Real, which uses the ideas of effective homology to sketch an algorithm for the homotopy groups of spheres specifically.