Morbid Angel is an American death metal band based in Tampa, Florida formed in 1983 by guitarist and sole remaining original member Trey Azagthoth, vocalist and bassist Dallas Ward, and drummer Mike Browning. Widely considered as one of the most influential bands in the genre and important in the transition of death metal from its thrash metal roots, they were one of the first bands to incorporate guttural vocals, up-tempo blast beats, multiple tempo changes and dark atmosphere. They have been described as one of "the most influential and emulated bands in death metal", alongside Obituary and Cannibal Corpse, and have been cited as an influence by many later bands. They were also the first death metal band to experience mainstream success in connection with being signed to Giant Records in 1992, heavy rotation of their music videos on MTV, and having the music video for the song "God of Emptiness" shown on an episode of Beavis and Butt-head.

Morbid Angel was formed in 1983 in Tampa, Florida by guitarist Trey Azagthoth and drummer/vocalist Mike Browning. The band made their debut in 1987 on the New Renaissance Records record label. They recorded their debut album, Abominations of Desolation, in 1986, but the band was unsatisfied with the final product and it remained unreleased until 1991, printing 10,000 copies. In the early stages of their career the band developed a reputation for "gruesome stage antics."  In 1986, David Vincent joined the band, replacing Michael Manson and Sterling von Scarborough as vocalist and bassist respectively. Fellow Terrorizer drummer Pete Sandoval soon followed. Their first studio album, Altars of Madness, was released in 1989, and is regarded by many as one of the most important death metal albums of all time. It is also considered the first true death metal album. Music journalist Jason Birchmeier writes that:  Few albums struck a chord within the ears and minds of the late-'80s underground metal scene like Morbid Angel's Altars of Madness did at the end of the decade, setting a new precedent for metal bands to reach. With the arguable exception of Chuck Schuldiner's Death, never before had a heavy metal band carried their lightning-fast guitar riffs and equally spellbinding guitar solos into such horrific territory. Venom and Slayer redefined the extent to which a metal band could align itself with all things evil during the beginning of the decade, but Morbid Angel made these two groups sound like children's music compared to the Florida-based group's assaulting death metal sounds and their blasphemous lyrics.

Using a quote from the above article, answer the following question: How long before someone was replaced in the band?
In 1986, David Vincent joined the band, replacing Michael Manson