You can use a massive Regexp on the export JSON file. This is what I did to migrate my 2500 posts.
To avoid to loose your inbound links, you maybe need to create some rewrite from the old domain to the new one.
On my side :
- I created a rewrite.json file from the admin portail to rewrite /post/2019/03/xxxx.html to the standard slug format.
- I created a NGINX rewrite to remove the .html extension on all the pages.
- I changed a function in Ghost to remove my old special chars from my URLs :
Need to rewrite special chars from my old blog URL - #3 by Ludovic_Toinel