Gaining trust requires immense patience over weeks, months. Rushing contact risks undoing progress. 

Establish set feeding routine so cats associate your presence with consistent positive reward they can depend on. 

Initially keep distance, tossing food nearer over subsequent days. Sit quietly, letting cat observe you're no threat.  

Containment allows closer interaction. Lure cat into humane trap or drop trap using food to safely contain. 

Use food rewards to positively reinforce desired Social Behaviors like tolerance of touch, petting while contained.

Note signs of progress in a journal. Record setbacks tracing issues needing more distance or rewards.  

Building real trust can take years for extremely fearful cats. Let that guide expectations of the process.