How to install a 4" recessed eyeball trim in 4" housings with a fixed socket

See what is needed to install a 4" recessed eyeball in standard 4" recessed housings with a fixed socket typically found at popular home improvement centers.
4" Recessed lighting black eyeball trim for R/Par 20 lamp
4" Recessed lighting black eyeball trim for R/Par 20 lamp
$13.82
SKU # TLS403BK

Out of stock

4" Recessed lighting chrome eyeball trim R/Par 20 lamp
4" Recessed lighting chrome eyeball trim R/Par 20 lamp
$12.44
SKU # TLS403CH
1 - 14 Day lead time
4" Recessed lighting polished brass eyeball trim for R/Par 20 lamp
4" Recessed lighting polished brass eyeball trim for R/Par 20 lamp
$17.99
SKU # TLS403PB
1 - 14 Day lead time
4" Recessed lighting white square eyeball trim
4" Recessed lighting white square eyeball trim
$13.82
SKU # TLS441WH
1 - 14 Day lead time
4" Recessed lighting chrome square regressed eyeball trim
4" Recessed lighting chrome square regressed eyeball trim
$31.88
SKU # TLS442CH

Out of stock