Simplify the following text for a Grade 5 native English-speaking person.
Original: Gordini worked with Renault as an engine tuner and finally sold his firm to Renault which entered Renaultâ `` Gordini cars at the 24 Hours of Le Mans from 1962 until 1969 .
Simplified: Gordini worked with Renault as an engine tuner . He sold his firm to Renault .