Postupak asimilacije pojedinaca razlikuje se s vremenom. Jedina konstanta je da se novorođenčad i kronološki mladi humanoidi ubrzano postaruju i kirurški dobivaju implantate koji se ne mogu ukloniti bez umiranja pojedinca, jer su direktno povezani s mozgom. Također dobivaju očni usadak, prostetičku višenamjensku ruku, kao i osobni energetski oklop. Odrasli humanoidi se efektivnije asimiliraju ubrizgavanjem nanorobota u krv, kroz par tubula u ruci radilice.
<!--Assimilation by tubules is depicted on-screen as being a fast-acting process, with the victim's skin pigmentation turning gray with visible dark tracks forming within moments of contact. The individual is then taken away for complete assimilation by drones. Sometimes assimilated Borg have been noted to be neither male nor female.<ref>Zvjezdane staze: Nova generacija, Sezona 2, Epizoda 16 (Q tko?)</ref> One theory could be that their reproductive systems have been removed upon assimilation, yet drones such as Captain Picard and Seven of Nine are easily identified as male and female. Drones who have escaped the collective have also been shown to have a gender.
The individual has all traces of individuality removed and implants are attached to the new drone so it can become an integrated part of the collective. This method of assimilation is also shown to be much more surgical in nature.<ref>Star Trek: First Contact</ref> In ''Star Trek: First Contact'' a captured crew member is shown to have a forearm and an eye physically removed and replaced with cybernetic implants.
Because assimilation depends on nanoprobes, species with extremely advanced immune systems are able to resist assimilation. Thus far, [[Species 8472]] is the only race shown to be capable of completely rejecting assimilation attempts, but other species, such as the [[Hirogen]], have also proved more than a match, both physically and technologically against the Borg.<ref>Star Trek Voyager, season 3 episode 26 and Season 4 Episode 1 (Scorpion Parts 1 & 2)</ref> [[Phlox (Star Trek)|Phlox]] was able to partially resist the assimilation process in the ''[[Star Trek: Enterprise]]'' episode "[[Regeneration (Star Trek: Enterprise)|Regeneration]]".
Nanoprobes are microscopic machines that inhabit a Borg's body, bloodstream, and many cybernetic implants. The probes perform the function of maintaining the Borg cybernetic systems, as well as repairing damage to the organic parts of a Borg. They generate new technology inside a Borg when needed, as well as protecting them from many forms of disease. Borg nanoprobes, each about the size of a human [[red blood cell]], travel through the victim's bloodstream and latch on to individual [[cell (biology)|cells]]. The nanoprobes rewrite the cellular [[DNA]], altering the victim's biochemistry, and eventually form larger, more complicated structures and networks within the body such as electrical pathways, processing and data-storage nodes, and ultimately prosthetic devices that spring forth from the skin. In "[[Mortal Coil (Star Trek: Voyager)|Mortal Coil]]", Seven of Nine states that the Borg assimilated the nanoprobe technology from "Species 149".
Though used by the Borg to exert control over another being, reprogrammed nanoprobes were used by the crew of the starship ''Voyager'' in many instances as medical aids. In one instance, the probes were used to revive crewman [[Neelix]] 18 hours, 49 minutes, and 13 seconds after death by repairing his body, and are used to treat various visitors' ailments.