You have the option of (1) replacing the wiring loom, (2) do a wire repair yourself, (3) get someone to repair it for you or (4) try to get the connector apart but this is a risk.
1. Don't know about the td4 but I have just had a look at the C0243 plug on my v6 as I couldn't find the C0243 only harness in microcat. C0243 is also connected to the starter motor control wire, headlight, headlight levelling and radiator fans. There may also be other stuff. So it looks like it's a multi use wiring harness.
2. Buy a crimp tool and crimps like this
9" Crimping Tool Ratchet Type, Plus 100 Mixed Crimping Terminals | eBay
(cheaper tools are available but they're crimping is crap and not ideal for the job) and some wire like this
RED - THINWALL 1mm sq Automotive Loom Cable / Wire 16.5A ? per 5 metres | eBay
and repair it yourself.
Disconnect the battery. You will need to cut the broken wire where it enters the barrel connector C0243 on both sides of the connector. Now cut open the outer protection on the harness to reveal the inner wires. Pull the faulty wire to one side and strip back the outer coating to reveal the copper wires inside the faulty cable, by 7mm. Use the crimp tool and the fully insulated crimps in the ebay listing (middle option second row up in the box) and crimp one crimp onto the faulty wire, and the other end of the same crimp on the wire you purchased. Now run the purchased wire past the C0243 connector towards the other end of the faulty wire which you cut earlier, to meet with the cut end of the harness. Allow a little extra purchase cable so it's not pulled tight or the stress on it will break it first. Now connect the purchased cable to the faulty cable with a fully covered crimp like before. Now connect the battery, put the rear window up and your Freelanders broken wire should be fixed ok with this repair. Tie wrap the purchased wire to the harness and make sure it's not pulled tight or it will break. If you don't want to use crimps as above then use choc block like this
15 AMP 15A 12 WAY CONNECTOR CABLE LEAD STRIP TERMINAL CHOC BLOCK ELECTRICAL | eBay
and some of the purchased cable as above. The choc block has screw terminals. It's best to use bootlace ferrule crimps like this
RED 1.0mm FERRULE CRIMP (BOOTLACE CRIMPS) QTY=50 | eBay (other sizes available) and bootlace ferrule tool
HS-26TW Twin Bootlace Ferrule Crimping Tool | eBay
(or something similar) to put a crimp on the wire first, and then secure the crimped wire in the choc block for a better connection. You'll need 2x 1 connector block (you can cut them off the strip) and 4 bootlace crimps (2 for the faulty wire and 2 for the purchased cable). Not everyone likes using choc block on electrical wires on cars. I understand their view but it's useful and when done properly can provide a good enough fix. You can fix video's or wiring harness repair on youtube to help. Always work with the power off (battery disconnected).
3. Get an auto electrician to carry out step 2 for you.
4. Try and get C0243 connector open but make sure you know which wire goes where and disconnect the battery first. It looks like it's held together from inside. You release the centre black plastic part which is held in place by the lugs on the inside. I don't think this will solve the problem as it's probably a case the wire has come off the pin inside and you'll strucggle to reconnect it again.