Slowly, and with some difficulty. Depending on where the party you wish to sue is based, permission of the English/Welsh court may be required before a claim can be issued at all.
If permission is required, you would have to apply to the court (in England or Wales) where the claim is to be issued, for permission to serve it out of the court's jurisdiction. The defendant will have to be given longer to respond than a defendant in England or Wales would get, the length of time depending on the country in which the claim is to be served.
If you find yourself in this position, consult your solicitor before you do anything. He (or she) may be able to suggest a more commercial way of achieving your objectives, possibly including advice as to whether you may be able to sue in the country in which the debtor is based.
