The phrase "without trouble" can be replaced by various synonyms depending on the context of the sentence. For instance, you could use "effortlessly," which implies that something is done without exertion or strain. Another synonym could be "smoothly," which emphasizes that the task was carried out without any interruptions or complications. "Seamlessly" is another alternative that suggests a process moves from one stage to another with no hitches or bumps along the way. Additionally, "flawlessly" and "easily" are synonyms that convey the idea that something was done with ease and without any hindrances.