Assumes you've already downloaded the Windows installer to your desktop. For more details see
this post.
mkdir /Library/flex2
cd /Library/flex2
unzip ~/Desktop/FlexBuilder2_Beta1_Install.exe InstallerData/Disk1/InstData/Resource1.zip -d tmp
unzip tmp/InstallerData/Disk1/InstData/Resource1.zip D_/builds/StagedZornSingleInstaller/subinstallers/WindowsCommon/mergemodules_zg_ia_sf.jar -d tmp
unzip tmp/D_/builds/StagedZornSingleInstaller/subinstallers/WindowsCommon/mergemodules_zg_ia_sf.jar FlexFrameworkMergeModule.iam.zip -d tmp
unzip tmp/FlexFrameworkMergeModule.iam.zip \$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/0bd81c0146bf21a847b3f37b3b4a0a53_zg_ia_sf.jar -d tmp
unzip tmp/FlexFrameworkMergeModule.iam.zip \$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/4c8bc042b3ca7b0232260983170d7827_zg_ia_sf.jar -d tmp
unzip tmp/FlexFrameworkMergeModule.iam.zip \$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/b132434261e44543bd04561ab89768a5_zg_ia_sf.jar -d tmp
unzip tmp/\$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/0bd81c0146bf21a847b3f37b3b4a0a53_zg_ia_sf.jar -d samples
unzip tmp/\$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/4c8bc042b3ca7b0232260983170d7827_zg_ia_sf.jar -d lib
unzip tmp/\$IA_MERGE_RESOURCES\$/FlexFrameworkMergeModule_1138525373520/b132434261e44543bd04561ab89768a5_zg_ia_sf.jar -d frameworks
rm -R tmp