firstly you need learn unpack aspack without IMPREC;
just dump in debugger @ good moment & locate original IT;
(btw, also there are dumpers for aspack..)

then,
join last 3 section (.rsrc .aspack .adata) under .rsrc section,
open in PExplorer & save as new file;

PExplorer will optimize joined .rsrc section..
(but sometimes bad~`)