macOS Mojave 10.14上安装iTunes12.6

将一下内容保存为iTunes.scpt，并运行

set question to display dialog "确定是否删除 iTunes ?" buttons {"Yes", "No"} default button 1
set answer to button returned of question
if answer is equal to "Yes" then
	do shell script "rm -rf /Applications/iTunes.app" with administrator privileges
	display dialog "iTunes 已删除" buttons {"OK"}
	set theDMG to choose file with prompt "请选择 iTunes 12.6 dmg 安装文件:" of type {"dmg"}
	do shell script "hdiutil mount " & quoted form of POSIX path of theDMG
	do shell script "pkgutil --expand /Volumes/iTunes/Install\\ iTunes.pkg ~/tmp"
	do shell script "sed -i '' 's/18A1/14F2511/g' ~/tmp/Distribution"
	do shell script "sed -i '' 's/gt/lt/g' ~/tmp/Distribution"
	do shell script "pkgutil --flatten ~/tmp ~/Desktop/iTunes.pkg"
	do shell script "hdiutil unmount /Volumes/iTunes/"
	do shell script "rm -rf ~/tmp"
end if
if answer is equal to "No" then
	display dialog "iTunes 未删除" buttons {"OK"}
	return
end if

set question to display dialog "确定是否安装 iTtunes 12.6 ?" buttons {"Yes", "No"} default button 1
set answer to button returned of question
if answer is equal to "Yes" then
	do shell script "open ~/Desktop/iTunes.pkg"
	return
end if
if answer is equal to "No" then
	display dialog "已修改的 iTunes.pkg 文件保存在桌面" buttons {"OK"}
	return
end if

参考资料：https://tinyurl.com/y33j2pwt https://forums.macrumors.com/threads/apples-special-version-of-itunes-that-still-has-an-app-store-currently-incompatible-with-macos-mojave.2143244/page-4#post-26592234