There are a good number of instances where Woolf changes the focalizing character although it is not precisely correct to say she changes the point of view. The point of view all throughout is given by a third person narrator who focalizes the story through one then another then another character. Technically, this is an omniscient third person narrator who has access to the thoughts, feelings and motives of any or all characters. Experientially, though, it may feel to some more like limited third person because of the techniques Woolf uses including pervasive stream of consciousness. Here are a few random quotes to establish point of view is consistently a third person narrator.

Beginning: "Mrs. Dalloway said she would buy the flowers herself." [she, herself]
Middle: "For example, Lady Bradshaw. Fifteen years ago she had gone under. ... Sweet was her smile ...." [she, her]
End: "he sat on for a moment. ... what is this ecstasy? he thought to himself.
   "It is Clarissa, he said." [he, himself]

We've established that the point of view is consistently third-person from beginning to end. Now let's tackle who the story is focalized through. Woolf continually changes the focalizer in the story: the character through whom our attention is focused on various characters or events.

Focalization leads directly to Woolf's methods for transitioning. Woolf begins by focalizing the story through Mrs. Dalloway (Clarissa.). While she is walking out shopping, the focalizer shifts to Scrope Purvis who describes Mrs. Dalloway ("very white since her illness"). The focalizer shifts again to Lucrezia and Septimus who lead us deeper into one of the important themes of the story: illness and death. Jumping to the end of the story, the focalizer shifts to Peter Walsh who gives a deeper look into Clarissa's inner being.

There are myriad other shifts in the focalizer. Each shift in focalization has the feel of a shift from one limited third-person POV to another limited third-person POV. Woolf has two main techniques for accomplishing this. The first technique is stream of consciousness. At each shift, she provides an indirect look into the the character's thoughts. It is an indirect look because the narrator doesn't rally quote the person; the narrator merely reports the character's thoughts. Purvis serves as a good example.

"A charming woman, Scrope Purvis thought her ...." Here, the narrator is passing on his thought as he thinks it. Were "A charming woman" a direct quotation, it would have been in quotation marks and tagged simply with "Scrope Purvis thought." Woolf specifies "thought her" to deviate from the norm so as to alert us to the direct connection with Purvis's stream of consciousness.

The second technique is to use external events in the setting as a fluid connection between various characters in various parts of the city. The most obvious example is the "aeroplane" in the sky spelling out the letters "a T, an O, an F." It is easy to understand that many people in many locations can see the same event at the same time. What Woolf did was to look up in one location to the sky through the eyes of one character, follow the plane as it flew through the sky, then look down from the plane to another location and another character.

Woolf employs this fluid setting many times and with many means. Another is the car that backfires out in front of the flower shop, stopping all "Passers-by." It introduces Septimus then drives down Bond Street to Fleet Street, then to Buckingham Palace where other characters speak their minds. The aeroplane, of course, then joins them and leads us from the Palace back to Regent’s Park and Septimus again. So two of Woolf's key techniques are stream of consciousness and fluid settings with multiple-witness events.