Slackware Upgrade to txz package's use

download from any mirror from current in "a" are left .tgz packages that is neded:

I use this mirror "http://mirrors.unixsol.org/slackware/slackware-current/slackware/a/"
Step by step - it is important to maintain this steps,

upgradepkg slackware/ap/slackpkg-2.71.2-noarch-1.tgz - custum
upgradepkg --install-new slackware/a/xz-4.999.8beta-i486-1.tgz
upgradepkg --install-new slackware/a/gzip-1.3.12-i486-1.tgz
upgradepkg --install-new slackware/a/tar-1.22-i486-2.tgz
upgradepkg --install-new slackware/a/pkgtools-12.34567890-noarch-5.tgz

That s all.