Hi!
Cut off the tip of the syringe just before it widens in order to hold the plunger in but allow the fibre in rough ground critical care or in mushed up pellets to pass out. A pair of scissors should do the trick.
PLEASE also accept that we don't like the expression 'force feeding' for a very important reason: just squirting the contents of a syringe into the mouth without doing so very gently and slowly, and only as much as a piggy can hold in its mouth and ONLY ever after they have swallowed the previous lot can lead to aspiration (the feed ending up in the lungs) or blocking the nose. We prefer to call support feeding 'syringe feeding'.
Here is our very detailed practical step-by-step feeding guide:
Complete Syringe Feeding Guide
Is your lady on analgesics (painkiller and anti-inflammatories) and on a glucosamine product to help strengthen the badly scratched and irritated natural glucosamine layer that prevents the corrosive urine from coming into contact with raw tissue?
Emergency, Crisis and Bridging Care until a Vet Appointment
PS: Fine ground recovery formula is usually easier to give and generally better accepted by piggies. Something you may want to look out for in the future; just as helpful tip. Look closely before ordering. If she doesn't like the taste of the CC, see whether mixing it with some mushed pellets will help.