Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, thank you for trusting us and for your question that shows your strong desire to perform Prayers and fasting.
As for your query, you just need to change the diaper and perform ablution (wudu’) for each prayer.
Responding to your question, Dr. Muhammad Salama, PhD in Islamic Studies in English and an Assistant Professor at the Faculty of Islamic Science, Al-Madinah International University, states:
May Allah Almighty grant you quick recovery. People with urinary incontinence still have to perform Prayer. You just need to take it easy and know that you have a license in this case that relieves you from this hardship.
For every obligatory Prayer, you need to change the diaper and clean yourself and then perform Prayer and forget about the urine that comes out thereafter. You can also perform voluntary Prayers with the same ablution (wudu’).