Has anyone done this, is it a simple means of pulling off the old and buying new?

Also what is the part number I should be looking for?

This is for passenger door window.

I believe this is the part I need? https://www.ebay.co.uk/itm/Genuine-Ford-Fiesta-MK7-N-S-Windscreen-Weatherstrip-Insert-Moulding-1746911-/393418805385?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0

If I remember correctly there is a Ford technical service builtin regarding this issue. It involves cutting through some of the steel wire reinforcement at several point on the new weather strip.

See the post below this for TSB details

On 11/21/2017 at 4:17 PM, JW1982 said:

It took me a while to find the TSB but I found it online.

 

Below some relevant information from this TSB:

 

Service Information:
Damage symptoms of the door weatherstrip (Focus 2011.25 front door shown, all other similar)
NOTE: It would not be possible that these two different damage symptoms (1 & 2) are called at same time.

 
1: Slightly stripped off and partially removed front door weatherstrip on the door underside

 2: Partially removed front door weatherstrip in the area of the door latch
 

Service Instruction:

Attach the door weatherstrip to the door frame

 

1: WARNING: Safety instructions of material equipment provided by the manufacturer must be observed.

Prepare the repair adhesive kit. Refer to the manufacturer's directions.

2: In reference to the damage symptom, the inside vulcanised fine wire should be cut.

1: Bend the door weatherstrip to get access to the inside vulcanised fine wire.

 

CAUTION: Do not damage the paint surface. The wire snap can audible be observed.

 

2: Briefly cut through the fine wire.

3: Range of separation for partially removed weatherstrips in the area of the door latch.

4: Range of separation for partially removed weatherstrips on the door underside.
◦Clean and dry the repair area. It is not required to remove any remaining traces of adhesive from the door frame.

 

 

 

3: NOTE: Allow the repair adhesive to dry (drying time ≥ 1 hour).

Apply repair adhesive (see Parts Required) to the door weatherstrip (door underside shown, other repair areas similar).
◦Max. Ø of adhesive bead: 3 mm

 

 

4: Place the door weatherstrip on the door frame in the correct position. Secure the door weatherstrip on the door frame using tape (door underside shown, other repair areas similar).

 

 
 

5: NOTE: If the ambient temperature falls below 10°C, apply warm air (25°C) continuously.

Press the door outer weatherstrip home for at least one minute in order to obtain complete adhesion (door underside shown, other repair areas similar).

1: Using a suitable plastic roller to press-on the weatherstrip. make sure that equal pressure is applied to the component.

2: Carefully check the correct position of the weatherstrip on the door frame.
◦Allow the repair adhesive to dry in reference to the manufacturers' directions but not less than 5 hours.
◦Remove any used tape.

 

 

6.If required, repeat steps 2 to 5 on the remaining doors.