A panel of experts on Thursday urged changes to three venues for the 2020 Olympics in the face of ballooning costs but organisers say such adjustments may prove difficult to instigate in time for the Games.
S A panel →どんな [of] experts
O changes →どんな [to] three venues →どんな [for] the 2020 Olympics
[in] the face →どんな [of] ballooning costs
S (such) adjustments
V [may prove]
O difficult →どんな [to] instigate
[in] time →どんな [for] the Games.